[Qemu-devel] [PATCH v2 0/8] target-arm: Fix Neon instructions VQMOVUN VQRSHL VQRSHRN VQRSHRUN VQSHRN VQSHRUN VSLI VSRI

[Qemu-devel] [PATCH v2 0/8] target-arm: Fix Neon instructions VQMOVUN VQRSHL VQRSHRN VQRSHRUN VQSHRN VQSHRUN VSLI VSRI

[christophe.lyon]

From: Christophe Lyon <christophe.lyon@st.com>

This patchset combines fixes from the Meego tree (Peter Maydell, Juha
Riihimäki) and my own fixes such that ARM Neon instructions VQMOVUN
VQRSHL VQRSHRN VQRSHRUN VQSHRN VQSHRUN VSLI VSRI now pass all my
tests.

Christophe Lyon (3):
  Fixes for several shift instructions: VRSHL, VRSHR, VRSHRN, VSHLL,
    VRSRA.
  target-arm: Fix Neon VQ(R)SHRN instructions.
  target-arm: Fix VQRSHL Neon instructions (signed/unsigned 64 bits and
        signed 32 bits variants).

Juha Riihimäki (1):
  target-arm: fix neon vqrshl instruction

Meego (4):
  Create and use neon_unarrow_sat* helpers
  VQRSHRN related changes
  fiddle decoding of 64 bit shift by imm and narrow
  implement vsli.64, vsri.64

 target-arm/helpers.h     |    3 +
 target-arm/neon_helper.c |  195 ++++++++++++++++++++++++++++++++++++++++++----
 target-arm/translate.c   |   98 +++++++++++++++++------
 3 files changed, 253 insertions(+), 43 deletions(-)

-- 
1.7.2.3

[Qemu-devel] [PATCH 1/8] target-arm: Fixes for several shift instructions: VRSHL, VRSHR, VRSHRN, VSHLL, VRSRA.

[christophe.lyon]

From: Christophe Lyon <christophe.lyon@st.com>

For variants with rounding, fix cases where adding the rounding
constant could overflow.

For VSHLL, fix bit mask.

Signed-off-by: Christophe Lyon <christophe.lyon@st.com>
---
 target-arm/neon_helper.c |   61 ++++++++++++++++++++++++++++++++++++++-------
 target-arm/translate.c   |   12 +++++++-
 2 files changed, 61 insertions(+), 12 deletions(-)

diff --git a/target-arm/neon_helper.c b/target-arm/neon_helper.c
index fead152..6c832b4 100644
--- a/target-arm/neon_helper.c
+++ b/target-arm/neon_helper.c
@@ -451,6 +451,9 @@ uint64_t HELPER(neon_shl_s64)(uint64_t valop, uint64_t shiftop)
     return val;
 }
 
+/* The addition of the rounding constant may overflow, so we use an
+ * intermediate 64 bits accumulator, which is really needed only when
+ * dealing with 32 bits input values.  */
 #define NEON_FN(dest, src1, src2) do { \
     int8_t tmp; \
     tmp = (int8_t)src2; \
@@ -459,11 +462,12 @@ uint64_t HELPER(neon_shl_s64)(uint64_t valop, uint64_t shiftop)
     } else if (tmp < -(ssize_t)sizeof(src1) * 8) { \
         dest = src1 >> (sizeof(src1) * 8 - 1); \
     } else if (tmp == -(ssize_t)sizeof(src1) * 8) { \
-        dest = src1 >> (tmp - 1); \
+        dest = src1 >> (-tmp - 1); \
         dest++; \
         dest >>= 1; \
     } else if (tmp < 0) { \
-        dest = (src1 + (1 << (-1 - tmp))) >> -tmp; \
+        int64_t big_dest = ((int64_t)src1 + (1 << (-1 - tmp))); \
+        dest = big_dest >> -tmp; \
     } else { \
         dest = src1 << tmp; \
     }} while (0)
@@ -472,6 +476,8 @@ NEON_VOP(rshl_s16, neon_s16, 2)
 NEON_VOP(rshl_s32, neon_s32, 1)
 #undef NEON_FN
 
+/* Handling addition overflow with 64 bits inputs values is more
+ * tricky than with 32 bits values.  */
 uint64_t HELPER(neon_rshl_s64)(uint64_t valop, uint64_t shiftop)
 {
     int8_t shift = (int8_t)shiftop;
@@ -480,18 +486,37 @@ uint64_t HELPER(neon_rshl_s64)(uint64_t valop, uint64_t shiftop)
         val = 0;
     } else if (shift < -64) {
         val >>= 63;
-    } else if (shift == -63) {
+    } else if (shift == -64) {
         val >>= 63;
         val++;
         val >>= 1;
     } else if (shift < 0) {
-        val = (val + ((int64_t)1 << (-1 - shift))) >> -shift;
+        int64_t round = (int64_t)1 << (-1 - shift);
+        /* Reduce the range as long as the addition overflows.  It's
+         * sufficient to check if (val+round) is < 0 and val > 0
+         * because round is > 0.  */
+        while ((val > 0) && ((val + round) < 0) && round > 1) {
+            shift++;
+            round >>= 1;
+            val >>= 1;
+        }
+        if ((val > 0) && (val + round) < 0) {
+            /* If addition still overflows at this point, it means
+             * that round==1, thus shift==-1, and also that
+             * val==0x7FFFFFFFFFFFFFFF.  */
+            val = 0x4000000000000000LL;
+        } else {
+            val = (val + round) >> -shift;
+        }
     } else {
         val <<= shift;
     }
     return val;
 }
 
+/* The addition of the rounding constant may overflow, so we use an
+ * intermediate 64 bits accumulator, which is really needed only when
+ * dealing with 32 bits input values.  */
 #define NEON_FN(dest, src1, src2) do { \
     int8_t tmp; \
     tmp = (int8_t)src2; \
@@ -499,9 +524,10 @@ uint64_t HELPER(neon_rshl_s64)(uint64_t valop, uint64_t shiftop)
         tmp < -(ssize_t)sizeof(src1) * 8) { \
         dest = 0; \
     } else if (tmp == -(ssize_t)sizeof(src1) * 8) { \
-        dest = src1 >> (tmp - 1); \
+        dest = src1 >> (-tmp - 1); \
     } else if (tmp < 0) { \
-        dest = (src1 + (1 << (-1 - tmp))) >> -tmp; \
+        uint64_t big_dest = ((uint64_t)src1 + (1 << (-1 - tmp))); \
+        dest = big_dest >> -tmp; \
     } else { \
         dest = src1 << tmp; \
     }} while (0)
@@ -513,14 +539,29 @@ NEON_VOP(rshl_u32, neon_u32, 1)
 uint64_t HELPER(neon_rshl_u64)(uint64_t val, uint64_t shiftop)
 {
     int8_t shift = (uint8_t)shiftop;
-    if (shift >= 64 || shift < 64) {
+    if (shift >= 64 || shift < -64) {
         val = 0;
     } else if (shift == -64) {
         /* Rounding a 1-bit result just preserves that bit.  */
         val >>= 63;
-    } if (shift < 0) {
-        val = (val + ((uint64_t)1 << (-1 - shift))) >> -shift;
-        val >>= -shift;
+    } else if (shift < 0) {
+        uint64_t round = (uint64_t)1 << (-1 - shift);
+        /* Reduce the range as long as the addition overflows.  It's
+         * sufficient to check if (val+round) is < val
+         * because val and round are > 0.  */
+        while (((val + round) < val) && round > 1) {
+            shift++;
+            round >>= 1;
+            val >>= 1;
+        }
+        if ((val + round) < val) {
+            /* If addition still overflows at this point, it means
+             * that round==1, thus shift==-1, and also that
+             * val==0x&FFFFFFFFFFFFFFF.  */
+            val = 0x8000000000000000LL;
+        } else {
+            val = (val + round) >> -shift;
+        }
     } else {
         val <<= shift;
     }
diff --git a/target-arm/translate.c b/target-arm/translate.c
index d95133f..b44f7a1 100644
--- a/target-arm/translate.c
+++ b/target-arm/translate.c
@@ -4877,10 +4877,18 @@ static int disas_neon_data_insn(CPUState * env, DisasContext *s, uint32_t insn)
                             if (size == 0) {
                                 imm = (0xffu >> (8 - shift));
                                 imm |= imm << 16;
-                            } else {
+                            } else if (size == 1) {
                                 imm = 0xffff >> (16 - shift);
+                            } else {
+                                /* size == 2 */
+                                imm = 0xffffffff >> (32 - shift);
+                            }
+                            if (size < 2) {
+                                imm64 = imm | (((uint64_t)imm) << 32);
+                            } else {
+                                imm64 = imm;
                             }
-                            imm64 = imm | (((uint64_t)imm) << 32);
+                            imm64 = ~imm64;
                             tcg_gen_andi_i64(cpu_V0, cpu_V0, imm64);
                         }
                     }
-- 
1.7.2.3

[Qemu-devel] [PATCH 2/8] target-arm: Create and use neon_unarrow_sat* helpers

[christophe.lyon]

From: Christophe Lyon <christophe.lyon@st.com>

Fix VQMOVUN, improve VQSHRUN and VQRSHRUN.

Signed-off-by: Christophe Lyon <christophe.lyon@st.com>
---
 target-arm/helpers.h     |    3 ++
 target-arm/neon_helper.c |   63 ++++++++++++++++++++++++++++++++++++++++++++++
 target-arm/translate.c   |   43 ++++++++++++++++++++++---------
 3 files changed, 96 insertions(+), 13 deletions(-)

diff --git a/target-arm/helpers.h b/target-arm/helpers.h
index b88ebae..8cc6a44 100644
--- a/target-arm/helpers.h
+++ b/target-arm/helpers.h
@@ -295,10 +295,13 @@ DEF_HELPER_3(neon_qrdmulh_s32, i32, env, i32, i32)
 
 DEF_HELPER_1(neon_narrow_u8, i32, i64)
 DEF_HELPER_1(neon_narrow_u16, i32, i64)
+DEF_HELPER_2(neon_unarrow_sat8, i32, env, i64)
 DEF_HELPER_2(neon_narrow_sat_u8, i32, env, i64)
 DEF_HELPER_2(neon_narrow_sat_s8, i32, env, i64)
+DEF_HELPER_2(neon_unarrow_sat16, i32, env, i64)
 DEF_HELPER_2(neon_narrow_sat_u16, i32, env, i64)
 DEF_HELPER_2(neon_narrow_sat_s16, i32, env, i64)
+DEF_HELPER_2(neon_unarrow_sat32, i32, env, i64)
 DEF_HELPER_2(neon_narrow_sat_u32, i32, env, i64)
 DEF_HELPER_2(neon_narrow_sat_s32, i32, env, i64)
 DEF_HELPER_1(neon_narrow_high_u8, i32, i64)
diff --git a/target-arm/neon_helper.c b/target-arm/neon_helper.c
index 6c832b4..891b812 100644
--- a/target-arm/neon_helper.c
+++ b/target-arm/neon_helper.c
@@ -1005,6 +1005,33 @@ uint32_t HELPER(neon_narrow_round_high_u16)(uint64_t x)
     return ((x >> 16) & 0xffff) | ((x >> 32) & 0xffff0000);
 }
 
+uint32_t HELPER(neon_unarrow_sat8)(CPUState *env, uint64_t x)
+{
+    uint16_t s;
+    uint8_t d;
+    uint32_t res = 0;
+#define SAT8(n) \
+    s = x >> n; \
+    if (s & 0x8000) { \
+        SET_QC(); \
+    } else { \
+        if (s > 0xff) { \
+            d = 0xff; \
+            SET_QC(); \
+        } else  { \
+            d = s; \
+        } \
+        res |= (uint32_t)d << (n / 2); \
+    }
+    
+    SAT8(0);
+    SAT8(16);
+    SAT8(32);
+    SAT8(48);
+#undef SAT8
+    return res;
+}
+
 uint32_t HELPER(neon_narrow_sat_u8)(CPUState *env, uint64_t x)
 {
     uint16_t s;
@@ -1051,6 +1078,29 @@ uint32_t HELPER(neon_narrow_sat_s8)(CPUState *env, uint64_t x)
     return res;
 }
 
+uint32_t HELPER(neon_unarrow_sat16)(CPUState *env, uint64_t x)
+{
+    uint32_t high;
+    uint32_t low;
+    low = x;
+    if (low & 0x80000000) {
+        low = 0;
+        SET_QC();
+    } else if (low > 0xffff) {
+        low = 0xffff;
+        SET_QC();
+    }
+    high = x >> 32;
+    if (high & 0x80000000) {
+        high = 0;
+        SET_QC();
+    } else if (high > 0xffff) {
+        high = 0xffff;
+        SET_QC();
+    }
+    return low | (high << 16);
+}
+
 uint32_t HELPER(neon_narrow_sat_u16)(CPUState *env, uint64_t x)
 {
     uint32_t high;
@@ -1085,6 +1135,19 @@ uint32_t HELPER(neon_narrow_sat_s16)(CPUState *env, uint64_t x)
     return (uint16_t)low | (high << 16);
 }
 
+uint32_t HELPER(neon_unarrow_sat32)(CPUState *env, uint64_t x)
+{
+    if (x & 0x8000000000000000ull) {
+        SET_QC();
+        return 0;
+    }
+    if (x > 0xffffffffu) {
+        SET_QC();
+        return 0xffffffffu;
+    }
+    return x;
+}
+
 uint32_t HELPER(neon_narrow_sat_u32)(CPUState *env, uint64_t x)
 {
     if (x > 0xffffffffu) {
diff --git a/target-arm/translate.c b/target-arm/translate.c
index b44f7a1..6dd024d 100644
--- a/target-arm/translate.c
+++ b/target-arm/translate.c
@@ -4071,6 +4071,16 @@ static inline void gen_neon_narrow_satu(int size, TCGv dest, TCGv_i64 src)
     }
 }
 
+static inline void gen_neon_unarrow_sats(int size, TCGv dest, TCGv_i64 src)
+{
+    switch(size) {
+    case 0: gen_helper_neon_unarrow_sat8(dest, cpu_env, src); break;
+    case 1: gen_helper_neon_unarrow_sat16(dest, cpu_env, src); break;
+    case 2: gen_helper_neon_unarrow_sat32(dest, cpu_env, src); break;
+    default: abort();
+    }
+}
+
 static inline void gen_neon_shift_narrow(int size, TCGv var, TCGv shift,
                                          int q, int u)
 {
@@ -4841,13 +4851,14 @@ static int disas_neon_data_insn(CPUState * env, DisasContext *s, uint32_t insn)
                         dead_tmp(tmp3);
                     }
                     tmp = new_tmp();
-                    if (op == 8 && !u) {
-                        gen_neon_narrow(size - 1, tmp, cpu_V0);
-                    } else {
-                        if (op == 8)
-                            gen_neon_narrow_sats(size - 1, tmp, cpu_V0);
-                        else
-                            gen_neon_narrow_satu(size - 1, tmp, cpu_V0);
+                    if (op == 8) {
+                        if (u) { /* VQSHRUN / VQRSHRUN */
+                            gen_neon_unarrow_sats(size - 1, tmp, cpu_V0);
+                        } else { /* VSHRN / VRSHRN */
+                            gen_neon_narrow(size - 1, tmp, cpu_V0);
+                        }
+                    } else { /* VQSHRN / VQRSHRN */
+                        gen_neon_narrow_satu(size - 1, tmp, cpu_V0);
                     }
                     neon_store_reg(rd, pass, tmp);
                 } /* for pass */
@@ -5471,12 +5482,18 @@ static int disas_neon_data_insn(CPUState * env, DisasContext *s, uint32_t insn)
                     for (pass = 0; pass < 2; pass++) {
                         neon_load_reg64(cpu_V0, rm + pass);
                         tmp = new_tmp();
-                        if (op == 36 && q == 0) {
-                            gen_neon_narrow(size, tmp, cpu_V0);
-                        } else if (q) {
-                            gen_neon_narrow_satu(size, tmp, cpu_V0);
-                        } else {
-                            gen_neon_narrow_sats(size, tmp, cpu_V0);
+                        if (op == 36) {
+                            if (q) { /* VQMOVUN */
+                                gen_neon_unarrow_sats(size, tmp, cpu_V0);
+                            } else { /* VMOVN */
+                                gen_neon_narrow(size, tmp, cpu_V0);
+                            }
+                        } else { /* VQMOVN */
+                            if (q) {
+                                gen_neon_narrow_satu(size, tmp, cpu_V0);
+                            } else {
+                                gen_neon_narrow_sats(size, tmp, cpu_V0);
+                            }
                         }
                         if (pass == 0) {
                             tmp2 = tmp;
-- 
1.7.2.3

[Qemu-devel] [PATCH 3/8] target-arm: VQRSHRN related changes

[christophe.lyon]

From: Christophe Lyon <christophe.lyon@st.com>

More fixes for VQSHRN and VQSHRUN.

Signed-off-by: Christophe Lyon <christophe.lyon@st.com>
---
 target-arm/translate.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/target-arm/translate.c b/target-arm/translate.c
index 6dd024d..9ca5b82 100644
--- a/target-arm/translate.c
+++ b/target-arm/translate.c
@@ -4101,8 +4101,8 @@ static inline void gen_neon_shift_narrow(int size, TCGv var, TCGv shift,
     } else {
         if (u) {
             switch (size) {
-            case 1: gen_helper_neon_rshl_u16(var, var, shift); break;
-            case 2: gen_helper_neon_rshl_u32(var, var, shift); break;
+            case 1: gen_helper_neon_shl_u16(var, var, shift); break;
+            case 2: gen_helper_neon_shl_u32(var, var, shift); break;
             default: abort();
             }
         } else {
-- 
1.7.2.3

[Qemu-devel] [PATCH 4/8] target-arm: fiddle decoding of 64 bit shift by imm and narrow

[christophe.lyon]

From: Christophe Lyon <christophe.lyon@st.com>

Tweak decoding of the shift-by-imm and narrow 64 bit insns
(VSHRN, VRSHRN, VQSHRN, VQSHRUN, VQRSHRN, VQRSHRUN).

Signed-off-by: Christophe Lyon <christophe.lyon@st.com>
---
 target-arm/translate.c |   28 ++++++++++++++++++----------
 1 files changed, 18 insertions(+), 10 deletions(-)

diff --git a/target-arm/translate.c b/target-arm/translate.c
index 9ca5b82..a614e34 100644
--- a/target-arm/translate.c
+++ b/target-arm/translate.c
@@ -4831,21 +4831,29 @@ static int disas_neon_data_insn(CPUState * env, DisasContext *s, uint32_t insn)
                     if (size == 3) {
                         neon_load_reg64(cpu_V0, rm + pass);
                         if (q) {
-                          if (u)
-                            gen_helper_neon_rshl_u64(cpu_V0, cpu_V0, tmp64);
-                          else
-                            gen_helper_neon_rshl_s64(cpu_V0, cpu_V0, tmp64);
+                            if ((op == 8 && !u) || (op == 9 && u)) {
+                                gen_helper_neon_rshl_u64(cpu_V0, cpu_V0,
+                                                         tmp64);
+                            } else {
+                                gen_helper_neon_rshl_s64(cpu_V0, cpu_V0,
+                                                         tmp64);
+                            }
                         } else {
-                          if (u)
-                            gen_helper_neon_shl_u64(cpu_V0, cpu_V0, tmp64);
-                          else
-                            gen_helper_neon_shl_s64(cpu_V0, cpu_V0, tmp64);
+                            if ((op == 8 && !u) || (op == 9 && u)) {
+                                gen_helper_neon_shl_u64(cpu_V0, cpu_V0,
+                                                        tmp64);
+                            } else {
+                                gen_helper_neon_shl_s64(cpu_V0, cpu_V0,
+                                                        tmp64);
+                            }
                         }
                     } else {
                         tmp = neon_load_reg(rm + pass, 0);
-                        gen_neon_shift_narrow(size, tmp, tmp2, q, u);
+                        gen_neon_shift_narrow(size, tmp, tmp2, q,
+                                              (op == 8) ? !u : u);
                         tmp3 = neon_load_reg(rm + pass, 1);
-                        gen_neon_shift_narrow(size, tmp3, tmp2, q, u);
+                        gen_neon_shift_narrow(size, tmp3, tmp2, q,
+                                              (op == 8) ? !u : u);
                         tcg_gen_concat_i32_i64(cpu_V0, tmp, tmp3);
                         dead_tmp(tmp);
                         dead_tmp(tmp3);
-- 
1.7.2.3

[Qemu-devel] [PATCH 5/8] target-arm: fix neon vqrshl instruction

[christophe.lyon]

From: Christophe Lyon <christophe.lyon@st.com>

Signed-off-by: Juha Riihimäki <juha.riihimaki@nokia.com>
Signed-off-by: Christophe Lyon <christophe.lyon@st.com>
---
 target-arm/neon_helper.c |   21 ++++++++++++++++++---
 1 files changed, 18 insertions(+), 3 deletions(-)

diff --git a/target-arm/neon_helper.c b/target-arm/neon_helper.c
index 891b812..46fcdc4 100644
--- a/target-arm/neon_helper.c
+++ b/target-arm/neon_helper.c
@@ -736,9 +736,24 @@ uint64_t HELPER(neon_qshlu_s64)(CPUState *env, uint64_t valop, uint64_t shiftop)
     }} while (0)
 NEON_VOP_ENV(qrshl_u8, neon_u8, 4)
 NEON_VOP_ENV(qrshl_u16, neon_u16, 2)
-NEON_VOP_ENV(qrshl_u32, neon_u32, 1)
 #undef NEON_FN
 
+uint32_t HELPER(neon_qrshl_u32)(CPUState *env, uint32_t val, uint32_t shiftop)
+{
+    int8_t shift = (int8_t)shiftop;
+    if (shift < 0) {
+        val = ((uint64_t)val + (1 << (-1 - shift))) >> -shift;
+    } else {
+        uint32_t tmp = val;
+        val <<= shift;
+        if ((val >> shift) != tmp) {
+            SET_QC();
+            val = ~0;
+        }
+    }
+    return val;
+}
+
 uint64_t HELPER(neon_qrshl_u64)(CPUState *env, uint64_t val, uint64_t shiftop)
 {
     int8_t shift = (int8_t)shiftop;
@@ -764,7 +779,7 @@ uint64_t HELPER(neon_qrshl_u64)(CPUState *env, uint64_t val, uint64_t shiftop)
         dest = src1 << tmp; \
         if ((dest >> tmp) != src1) { \
             SET_QC(); \
-            dest = src1 >> 31; \
+            dest = (uint32_t)(1 << (sizeof(src1) * 8 - 1)) - (src1 > 0 ? 1 : 0); \
         } \
     }} while (0)
 NEON_VOP_ENV(qrshl_s8, neon_s8, 4)
@@ -780,7 +795,7 @@ uint64_t HELPER(neon_qrshl_s64)(CPUState *env, uint64_t valop, uint64_t shiftop)
     if (shift < 0) {
         val = (val + (1 << (-1 - shift))) >> -shift;
     } else {
-        int64_t tmp = val;;
+        int64_t tmp = val;
         val <<= shift;
         if ((val >> shift) != tmp) {
             SET_QC();
-- 
1.7.2.3

[Qemu-devel] [PATCH 6/8] target-arm: Fix Neon VQ(R)SHRN instructions.

[christophe.lyon]

From: Christophe Lyon <christophe.lyon@st.com>

Handle unsigned variant of VQ(R)SHRN instructions.

Signed-off-by: Christophe Lyon <christophe.lyon@st.com>
---
 target-arm/translate.c |    8 ++++++--
 1 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/target-arm/translate.c b/target-arm/translate.c
index a614e34..61d4c4c 100644
--- a/target-arm/translate.c
+++ b/target-arm/translate.c
@@ -4865,8 +4865,12 @@ static int disas_neon_data_insn(CPUState * env, DisasContext *s, uint32_t insn)
                         } else { /* VSHRN / VRSHRN */
                             gen_neon_narrow(size - 1, tmp, cpu_V0);
                         }
-                    } else { /* VQSHRN / VQRSHRN */
-                        gen_neon_narrow_satu(size - 1, tmp, cpu_V0);
+                    } else {
+                        if (u) { /* VQSHRUN / VQRSHRUN */
+                            gen_neon_narrow_satu(size - 1, tmp, cpu_V0);
+                        } else { /* VQSHRN / VQRSHRN */
+                            gen_neon_narrow_sats(size - 1, tmp, cpu_V0);
+                        }
                     }
                     neon_store_reg(rd, pass, tmp);
                 } /* for pass */
-- 
1.7.2.3

[Qemu-devel] [PATCH 7/8] target-arm: implement vsli.64, vsri.64

[christophe.lyon]

From: Christophe Lyon <christophe.lyon@st.com>

Signed-off-by: Christophe Lyon <christophe.lyon@st.com>
---
 target-arm/translate.c |   11 ++++++++++-
 1 files changed, 10 insertions(+), 1 deletions(-)

diff --git a/target-arm/translate.c b/target-arm/translate.c
index 61d4c4c..9150242 100644
--- a/target-arm/translate.c
+++ b/target-arm/translate.c
@@ -4700,7 +4700,16 @@ static int disas_neon_data_insn(CPUState * env, DisasContext *s, uint32_t insn)
                             tcg_gen_add_i64(cpu_V0, cpu_V0, cpu_V1);
                         } else if (op == 4 || (op == 5 && u)) {
                             /* Insert */
-                            cpu_abort(env, "VS[LR]I.64 not implemented");
+                            neon_load_reg64(cpu_V1, rd + pass);
+                            uint64_t mask;
+                            if (op == 4) {
+                                mask = 0xffffffffffffffffull >> -shift;
+                            } else {
+                                mask = 0xffffffffffffffffull << shift;
+                            }
+                            tcg_gen_andi_i64(cpu_V0, cpu_V0, mask);
+                            tcg_gen_andi_i64(cpu_V1, cpu_V1, ~mask);
+                            tcg_gen_or_i64(cpu_V0, cpu_V0, cpu_V1);
                         }
                         neon_store_reg64(cpu_V0, rd + pass);
                     } else { /* size < 3 */
-- 
1.7.2.3

[Qemu-devel] [PATCH 8/8] target-arm: Fix VQRSHL Neon instructions (signed/unsigned 64 bits and signed 32 bits variants).

[christophe.lyon]

From: Christophe Lyon <christophe.lyon@st.com>

The addition of the rounding constant could cause overflows.

Signed-off-by: Christophe Lyon <christophe.lyon@st.com>
---
 target-arm/neon_helper.c |   50 ++++++++++++++++++++++++++++++++++++++++++---
 1 files changed, 46 insertions(+), 4 deletions(-)

diff --git a/target-arm/neon_helper.c b/target-arm/neon_helper.c
index 46fcdc4..2f96575 100644
--- a/target-arm/neon_helper.c
+++ b/target-arm/neon_helper.c
@@ -758,7 +758,23 @@ uint64_t HELPER(neon_qrshl_u64)(CPUState *env, uint64_t val, uint64_t shiftop)
 {
     int8_t shift = (int8_t)shiftop;
     if (shift < 0) {
-        val = (val + (1 << (-1 - shift))) >> -shift;
+        uint64_t round = (uint64_t)1 << (-1 - shift);
+        /* Reduce the range as long as the addition overflows.  It's
+         * sufficient to check if (val+round) is < val
+         * because val and round are > 0.  */
+        while (((val + round) < val) && round > 1) {
+            shift++;
+            round >>= 1;
+            val >>= 1;
+        }
+        if ((val + round) < val) {
+            /* If addition still overflows at this point, it means
+             * that round==1, thus shift==-1, and also that
+             * val==0x&FFFFFFFFFFFFFFF.  */
+            val = 0x8000000000000000LL;
+        } else {
+            val = (val + round) >> -shift;
+        }
     } else { \
         uint64_t tmp = val;
         val <<= shift;
@@ -770,11 +786,15 @@ uint64_t HELPER(neon_qrshl_u64)(CPUState *env, uint64_t val, uint64_t shiftop)
     return val;
 }
 
+/* The addition of the rounding constant may overflow, so we use an
+ * intermediate 64 bits accumulator, which is really needed only when
+ * dealing with 32 bits input values.  */
 #define NEON_FN(dest, src1, src2) do { \
     int8_t tmp; \
     tmp = (int8_t)src2; \
     if (tmp < 0) { \
-        dest = (src1 + (1 << (-1 - tmp))) >> -tmp; \
+        int64_t big_dest = ((int64_t)src1 + (1 << (-1 - tmp))); \
+        dest = big_dest >> -tmp; \
     } else { \
         dest = src1 << tmp; \
         if ((dest >> tmp) != src1) { \
@@ -787,19 +807,41 @@ NEON_VOP_ENV(qrshl_s16, neon_s16, 2)
 NEON_VOP_ENV(qrshl_s32, neon_s32, 1)
 #undef NEON_FN
 
+/* Handling addition overflow with 64 bits inputs values is more
+ * tricky than with 32 bits values.  */
 uint64_t HELPER(neon_qrshl_s64)(CPUState *env, uint64_t valop, uint64_t shiftop)
 {
     int8_t shift = (uint8_t)shiftop;
     int64_t val = valop;
 
     if (shift < 0) {
-        val = (val + (1 << (-1 - shift))) >> -shift;
+        int64_t round = (int64_t)1 << (-1 - shift);
+        /* Reduce the range as long as the addition overflows.  It's
+         * sufficient to check if (val+round) is < 0 and val > 0
+         * because round is > 0.  */
+        while ((val > 0) && ((val + round) < 0) && round > 1) {
+            shift++;
+            round >>= 1;
+            val >>= 1;
+        }
+        if ((val > 0) && (val + round) < 0) {
+            /* If addition still overflows at this point, it means
+             * that round==1, thus shift==-1, and also that
+             * val==0x7FFFFFFFFFFFFFFF.  */
+            val = 0x4000000000000000LL;
+        } else {
+            val = (val + round) >> -shift;
+        }
     } else {
         int64_t tmp = val;
         val <<= shift;
         if ((val >> shift) != tmp) {
             SET_QC();
-            val = tmp >> 31;
+            if (tmp < 0) {
+                val = INT64_MIN;
+            } else {
+                val = INT64_MAX;
+            }
         }
     }
     return val;
-- 
1.7.2.3

Re: [Qemu-devel] [PATCH 7/8] target-arm: implement vsli.64, vsri.64

[Peter Maydell]

On 31 January 2011 18:06,  <christophe.lyon@st.com> wrote:
> From: Christophe Lyon <christophe.lyon@st.com>
>
> Signed-off-by: Christophe Lyon <christophe.lyon@st.com>
> ---
>  target-arm/translate.c |   11 ++++++++++-
>  1 files changed, 10 insertions(+), 1 deletions(-)
>
> diff --git a/target-arm/translate.c b/target-arm/translate.c
> index 61d4c4c..9150242 100644
> --- a/target-arm/translate.c
> +++ b/target-arm/translate.c
> @@ -4700,7 +4700,16 @@ static int disas_neon_data_insn(CPUState * env, DisasContext *s, uint32_t insn)
>                             tcg_gen_add_i64(cpu_V0, cpu_V0, cpu_V1);
>                         } else if (op == 4 || (op == 5 && u)) {
>                             /* Insert */
> -                            cpu_abort(env, "VS[LR]I.64 not implemented");
> +                            neon_load_reg64(cpu_V1, rd + pass);
> +                            uint64_t mask;
> +                            if (op == 4) {
> +                                mask = 0xffffffffffffffffull >> -shift;
> +                            } else {
> +                                mask = 0xffffffffffffffffull << shift;
> +                            }

If shift is 64 or -64 then the result of this shift is undefined (and for
an x86 host we get the wrong results for eg "vsri.64 q5,q5,64").

You want to add an
  if (shift < -63 || shift > 63) {
    mask = 0;
  } else ...

clause (compare the 32 bit case.)

> +                            tcg_gen_andi_i64(cpu_V0, cpu_V0, mask);

This AND is harmless but unnecessary (and not specified in the
ARM ARM.)

-- PMM

Re: [Qemu-devel] [PATCH 1/8] target-arm: Fixes for several shift instructions: VRSHL, VRSHR, VRSHRN, VSHLL, VRSRA.

[Peter Maydell]

On 31 January 2011 18:06,  <christophe.lyon@st.com> wrote:
> For variants with rounding, fix cases where adding the rounding
> constant could overflow.
>
> For VSHLL, fix bit mask.

These two things are completely distinct -- please put them
in separate patches.

-- PMM

Re: [Qemu-devel] [PATCH 6/8] target-arm: Fix Neon VQ(R)SHRN instructions.

[Peter Maydell]

On 31 January 2011 18:06,  <christophe.lyon@st.com> wrote:
> From: Christophe Lyon <christophe.lyon@st.com>
>
> Handle unsigned variant of VQ(R)SHRN instructions.

This patch appears to be modifying a section of code
that was already patched by 2/8 in this series. That's
too confusing to review -- please combine them into
one patch.

-- PMM

Re: [Qemu-devel] [PATCH 7/8] target-arm: implement vsli.64, vsri.64

[Peter Maydell]

On 7 February 2011 15:55, Peter Maydell <peter.maydell@linaro.org> wrote:
> On 31 January 2011 18:06,  <christophe.lyon@st.com> wrote:
>> From: Christophe Lyon <christophe.lyon@st.com>
>>
>> Signed-off-by: Christophe Lyon <christophe.lyon@st.com>

Incidentally, this patch works fine (when corrected) as a standalone
fix for these instructions, so you could just submit the reworked
version as a patch on its own if you don't want it to get tangled
up in review of the other patches in this series.

-- PMM

Re: [Qemu-devel] [PATCH 6/8] target-arm: Fix Neon VQ(R)SHRN instructions.

[Christophe Lyon]

On 07.02.2011 17:08, Peter Maydell wrote:
> On 31 January 2011 18:06,  <christophe.lyon@st.com> wrote:
>> From: Christophe Lyon <christophe.lyon@st.com>
>>
>> Handle unsigned variant of VQ(R)SHRN instructions.
> 
> This patch appears to be modifying a section of code
> that was already patched by 2/8 in this series. That's
> too confusing to review -- please combine them into
> one patch.
> 

That's because I borrowed patch 2/8 from your meego tree. It was incomplete, but as I preferred to keep it as-is, I completed it in a separate patch.

>From your other comments it looks like I'd have had better ignore the patches from Meego and rewrite the patches on my own ;-)

Re: [Qemu-devel] [PATCH 6/8] target-arm: Fix Neon VQ(R)SHRN instructions.

[Peter Maydell]

On 7 February 2011 16:50, Christophe Lyon <christophe.lyon@st.com> wrote:
> On 07.02.2011 17:08, Peter Maydell wrote:
>> On 31 January 2011 18:06,  <christophe.lyon@st.com> wrote:
>>> From: Christophe Lyon <christophe.lyon@st.com>
>>>
>>> Handle unsigned variant of VQ(R)SHRN instructions.
>>
>> This patch appears to be modifying a section of code
>> that was already patched by 2/8 in this series. That's
>> too confusing to review -- please combine them into
>> one patch.
>>
>
> That's because I borrowed patch 2/8 from your meego tree.
> It was incomplete, but as I preferred to keep it as-is, I
> completed it in a separate patch.
>
> From your other comments it looks like I'd have had better ignore
> the patches from Meego and rewrite the patches on my own ;-)

Well, you shouldn't ignore them, but part of the process of getting
those patches into upstream is cleaning them up: testing whether
they work, adding the cases where they don't, providing better
commit messages, splitting and combining them so that each
patch submitted upstream is a single easy to review logical change,
and so on. (It's exactly because this isn't a totally trivial process
that there's still a queue of non-upstreamed patches in that tree.)

-- PMM

Re: [Qemu-devel] [PATCH 3/8] target-arm: VQRSHRN related changes

[Peter Maydell]

On 31 January 2011 18:06,  <christophe.lyon@st.com> wrote:
> From: Christophe Lyon <christophe.lyon@st.com>
>
> More fixes for VQSHRN and VQSHRUN.
>
> Signed-off-by: Christophe Lyon <christophe.lyon@st.com>

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
as far as the code goes, but the commit message is
excessively vague.

-- PMM

Re: [Qemu-devel] [PATCH 4/8] target-arm: fiddle decoding of 64 bit shift by imm and narrow

[Peter Maydell]

On 31 January 2011 18:06,  <christophe.lyon@st.com> wrote:
> From: Christophe Lyon <christophe.lyon@st.com>
>
> Tweak decoding of the shift-by-imm and narrow 64 bit insns
> (VSHRN, VRSHRN, VQSHRN, VQSHRUN, VQRSHRN, VQRSHRUN).
>
> Signed-off-by: Christophe Lyon <christophe.lyon@st.com>
> ---
>  target-arm/translate.c |   28 ++++++++++++++++++----------
>  1 files changed, 18 insertions(+), 10 deletions(-)
>
> diff --git a/target-arm/translate.c b/target-arm/translate.c
> index 9ca5b82..a614e34 100644
> --- a/target-arm/translate.c
> +++ b/target-arm/translate.c
> @@ -4831,21 +4831,29 @@ static int disas_neon_data_insn(CPUState * env, DisasContext *s, uint32_t insn)
>                     if (size == 3) {
>                         neon_load_reg64(cpu_V0, rm + pass);
>                         if (q) {
> -                          if (u)
> -                            gen_helper_neon_rshl_u64(cpu_V0, cpu_V0, tmp64);
> -                          else
> -                            gen_helper_neon_rshl_s64(cpu_V0, cpu_V0, tmp64);
> +                            if ((op == 8 && !u) || (op == 9 && u)) {

This patch would improved if you started with:
                int input_unsigned = (op == 8) ? !u : u;
and then used that here and:

> +                            if ((op == 8 && !u) || (op == 9 && u)) {

here...

> +                        gen_neon_shift_narrow(size, tmp, tmp2, q,
> +                                              (op == 8) ? !u : u);

here...

> +                        gen_neon_shift_narrow(size, tmp3, tmp2, q,
> +                                              (op == 8) ? !u : u);

and here.

(What all these things are trying to check is whether the
input elements for the operations are signed or unsigned;
this isn't the same as the u bit, which is whether the output
is unsigned.)

-- PMM

Re: [Qemu-devel] [PATCH 1/8] target-arm: Fixes for several shift instructions: VRSHL, VRSHR, VRSHRN, VSHLL, VRSRA.

[Christophe Lyon]

On 07.02.2011 16:57, Peter Maydell wrote:
> On 31 January 2011 18:06,  <christophe.lyon@st.com> wrote:
>> For variants with rounding, fix cases where adding the rounding
>> constant could overflow.
>>
>> For VSHLL, fix bit mask.
> 
> These two things are completely distinct -- please put them
> in separate patches.
> 

OK, I am going to re-submit this whole series of patches.

Thanks

Christophe.

[Qemu-devel] [PATCH 6/8] target-arm: Fix Neon VQ(R)SHRN instructions.

[christophe.lyon]

From: Christophe Lyon <christophe.lyon@st.com>

Handle unsigned variant of VQ(R)SHRN instructions.

Signed-off-by: Christophe Lyon <christophe.lyon@st.com>
---
 target-arm/translate.c |    8 ++++++--
 1 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/target-arm/translate.c b/target-arm/translate.c
index 452cb71..3b14b8f 100644
--- a/target-arm/translate.c
+++ b/target-arm/translate.c
@@ -4876,8 +4876,12 @@ static int disas_neon_data_insn(CPUState * env, DisasContext *s, uint32_t insn)
                         } else { /* VSHRN / VRSHRN */
                             gen_neon_narrow(size - 1, tmp, cpu_V0);
                         }
-                    } else { /* VQSHRN / VQRSHRN */
-                        gen_neon_narrow_satu(size - 1, tmp, cpu_V0);
+                    } else {
+                        if (u) { /* VQSHRUN / VQRSHRUN */
+                            gen_neon_narrow_satu(size - 1, tmp, cpu_V0);
+                        } else { /* VQSHRN / VQRSHRN */
+                            gen_neon_narrow_sats(size - 1, tmp, cpu_V0);
+                        }
                     }
                     neon_store_reg(rd, pass, tmp);
                 } /* for pass */
-- 
1.7.2.3