[Qemu-devel] [PULL 0/4] M68k for 2.10 patches

[Qemu-devel] [PULL 0/4] M68k for 2.10 patches

[Laurent Vivier]

The following changes since commit 3f0602927b120a480b35dcf58cf6f95435b3ae91:

  Merge remote-tracking branch 'remotes/pmaydell/tags/pull-target-arm-20170613' into staging (2017-06-13 15:49:07 +0100)

are available in the git repository at:

  git://github.com/vivier/qemu-m68k.git tags/m68k-for-2.10-pull-request

for you to fetch changes up to 69e698220f68a17ce9584b068f68ed09e527a6ad:

  target-m68k: define ext_opsize (2017-06-15 09:16:38 +0200)

----------------------------------------------------------------

----------------------------------------------------------------

Laurent Vivier (4):
  target/m68k: fix V flag for CC_OP_SUBx
  softfloat: define 680x0 specific values
  target-m68k: move FPU helpers to fpu_helper.c
  target-m68k: define ext_opsize

 fpu/softfloat-specialize.h |  34 ++++++++++++--
 target/m68k/Makefile.objs  |   2 +-
 target/m68k/fpu_helper.c   | 112 +++++++++++++++++++++++++++++++++++++++++++++
 target/m68k/helper.c       |  88 -----------------------------------
 target/m68k/translate.c    |  45 ++++++++++--------
 5 files changed, 169 insertions(+), 112 deletions(-)
 create mode 100644 target/m68k/fpu_helper.c

-- 
2.9.4

[Qemu-devel] [PULL 1/4] target/m68k: fix V flag for CC_OP_SUBx

[Laurent Vivier]

V flag for subtraction is:

   v = (res ^ src1) & (src1 ^ src2)

(see COMPUTE_CCR() in target/m68k/helper.c)

But gen_flush_flags() uses:

   v = (res ^ src2) & (src1 ^ src2)

The problem has been found with the following program:

        .global _start
_start:
        move.l  #-2147483648,%d0
        subq.l  #1,%d0
        jvc     1f
        move.l #1,%d1
        move.l #1,%d0
        trap #0
1:
        move.l #0,%d1
        move.l #1,%d0
        trap #0

It works fine (exit(1)) on real hardware, and with "-singlestep".

"-singlestep" uses gen_helper_flush_flags(), whereas
without "-singlestep", V flag is computed directly in
gen_flush_flags().

This patch updates gen_flush_flags() to have the same result
as with gen_helper_flush_flags().

Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Message-Id: <20170614203905.19657-1-laurent@vivier.eu>
---
 target/m68k/translate.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/target/m68k/translate.c b/target/m68k/translate.c
index ad4d4ef..52653f6 100644
--- a/target/m68k/translate.c
+++ b/target/m68k/translate.c
@@ -565,7 +565,7 @@ static void gen_flush_flags(DisasContext *s)
         t1 = tcg_temp_new();
         tcg_gen_add_i32(t0, QREG_CC_N, QREG_CC_V);
         gen_ext(t0, t0, s->cc_op - CC_OP_SUBB, 1);
-        tcg_gen_xor_i32(t1, QREG_CC_N, QREG_CC_V);
+        tcg_gen_xor_i32(t1, QREG_CC_N, t0);
         tcg_gen_xor_i32(QREG_CC_V, QREG_CC_V, t0);
         tcg_temp_free(t0);
         tcg_gen_and_i32(QREG_CC_V, QREG_CC_V, t1);
-- 
2.9.4

[Qemu-devel] [PULL 2/4] softfloat: define 680x0 specific values

[Laurent Vivier]

Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Message-Id: <20170611231633.32582-2-laurent@vivier.eu>
---
 fpu/softfloat-specialize.h | 34 +++++++++++++++++++++++++++++++---
 1 file changed, 31 insertions(+), 3 deletions(-)

diff --git a/fpu/softfloat-specialize.h b/fpu/softfloat-specialize.h
index 100c8a9..de2c5d5 100644
--- a/fpu/softfloat-specialize.h
+++ b/fpu/softfloat-specialize.h
@@ -111,7 +111,7 @@ float16 float16_default_nan(float_status *status)
 *----------------------------------------------------------------------------*/
 float32 float32_default_nan(float_status *status)
 {
-#if defined(TARGET_SPARC)
+#if defined(TARGET_SPARC) || defined(TARGET_M68K)
     return const_float32(0x7FFFFFFF);
 #elif defined(TARGET_PPC) || defined(TARGET_ARM) || defined(TARGET_ALPHA) || \
       defined(TARGET_XTENSA) || defined(TARGET_S390X) || defined(TARGET_TRICORE)
@@ -136,7 +136,7 @@ float32 float32_default_nan(float_status *status)
 *----------------------------------------------------------------------------*/
 float64 float64_default_nan(float_status *status)
 {
-#if defined(TARGET_SPARC)
+#if defined(TARGET_SPARC) || defined(TARGET_M68K)
     return const_float64(LIT64(0x7FFFFFFFFFFFFFFF));
 #elif defined(TARGET_PPC) || defined(TARGET_ARM) || defined(TARGET_ALPHA) || \
       defined(TARGET_S390X)
@@ -162,7 +162,10 @@ float64 float64_default_nan(float_status *status)
 floatx80 floatx80_default_nan(float_status *status)
 {
     floatx80 r;
-
+#if defined(TARGET_M68K)
+    r.low = LIT64(0xFFFFFFFFFFFFFFFF);
+    r.high = 0x7FFF;
+#else
     if (status->snan_bit_is_one) {
         r.low = LIT64(0xBFFFFFFFFFFFFFFF);
         r.high = 0x7FFF;
@@ -170,6 +173,7 @@ floatx80 floatx80_default_nan(float_status *status)
         r.low = LIT64(0xC000000000000000);
         r.high = 0xFFFF;
     }
+#endif
     return r;
 }
 
@@ -502,6 +506,30 @@ static int pickNaN(flag aIsQNaN, flag aIsSNaN, flag bIsQNaN, flag bIsSNaN,
         return 1;
     }
 }
+#elif defined(TARGET_M68K)
+static int pickNaN(flag aIsQNaN, flag aIsSNaN, flag bIsQNaN, flag bIsSNaN,
+                   flag aIsLargerSignificand)
+{
+    /* M68000 FAMILY PROGRAMMER'S REFERENCE MANUAL
+     * 3.4 FLOATING-POINT INSTRUCTION DETAILS
+     * If either operand, but not both operands, of an operation is a
+     * nonsignaling NaN, then that NaN is returned as the result. If both
+     * operands are nonsignaling NaNs, then the destination operand
+     * nonsignaling NaN is returned as the result.
+     * If either operand to an operation is a signaling NaN (SNaN), then the
+     * SNaN bit is set in the FPSR EXC byte. If the SNaN exception enable bit
+     * is set in the FPCR ENABLE byte, then the exception is taken and the
+     * destination is not modified. If the SNaN exception enable bit is not
+     * set, setting the SNaN bit in the operand to a one converts the SNaN to
+     * a nonsignaling NaN. The operation then continues as described in the
+     * preceding paragraph for nonsignaling NaNs.
+     */
+    if (aIsQNaN || aIsSNaN) { /* a is the destination operand */
+        return 0; /* return the destination operand */
+    } else {
+        return 1; /* return b */
+    }
+}
 #else
 static int pickNaN(flag aIsQNaN, flag aIsSNaN, flag bIsQNaN, flag bIsSNaN,
                     flag aIsLargerSignificand)
-- 
2.9.4

[Qemu-devel] [PULL 3/4] target-m68k: move FPU helpers to fpu_helper.c

[Laurent Vivier]

Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Message-Id: <20170611231633.32582-3-laurent@vivier.eu>
---
 target/m68k/Makefile.objs |   2 +-
 target/m68k/fpu_helper.c  | 112 ++++++++++++++++++++++++++++++++++++++++++++++
 target/m68k/helper.c      |  88 ------------------------------------
 3 files changed, 113 insertions(+), 89 deletions(-)
 create mode 100644 target/m68k/fpu_helper.c

diff --git a/target/m68k/Makefile.objs b/target/m68k/Makefile.objs
index 02cf616..39141ab 100644
--- a/target/m68k/Makefile.objs
+++ b/target/m68k/Makefile.objs
@@ -1,3 +1,3 @@
 obj-y += m68k-semi.o
-obj-y += translate.o op_helper.o helper.o cpu.o
+obj-y += translate.o op_helper.o helper.o cpu.o fpu_helper.o
 obj-y += gdbstub.o
diff --git a/target/m68k/fpu_helper.c b/target/m68k/fpu_helper.c
new file mode 100644
index 0000000..5bf2576
--- /dev/null
+++ b/target/m68k/fpu_helper.c
@@ -0,0 +1,112 @@
+/*
+ *  m68k FPU helpers
+ *
+ *  Copyright (c) 2006-2007 CodeSourcery
+ *  Written by Paul Brook
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "qemu/osdep.h"
+#include "cpu.h"
+#include "exec/helper-proto.h"
+
+uint32_t HELPER(f64_to_i32)(CPUM68KState *env, float64 val)
+{
+    return float64_to_int32(val, &env->fp_status);
+}
+
+float32 HELPER(f64_to_f32)(CPUM68KState *env, float64 val)
+{
+    return float64_to_float32(val, &env->fp_status);
+}
+
+float64 HELPER(i32_to_f64)(CPUM68KState *env, uint32_t val)
+{
+    return int32_to_float64(val, &env->fp_status);
+}
+
+float64 HELPER(f32_to_f64)(CPUM68KState *env, float32 val)
+{
+    return float32_to_float64(val, &env->fp_status);
+}
+
+float64 HELPER(iround_f64)(CPUM68KState *env, float64 val)
+{
+    return float64_round_to_int(val, &env->fp_status);
+}
+
+float64 HELPER(itrunc_f64)(CPUM68KState *env, float64 val)
+{
+    return float64_trunc_to_int(val, &env->fp_status);
+}
+
+float64 HELPER(sqrt_f64)(CPUM68KState *env, float64 val)
+{
+    return float64_sqrt(val, &env->fp_status);
+}
+
+float64 HELPER(abs_f64)(float64 val)
+{
+    return float64_abs(val);
+}
+
+float64 HELPER(chs_f64)(float64 val)
+{
+    return float64_chs(val);
+}
+
+float64 HELPER(add_f64)(CPUM68KState *env, float64 a, float64 b)
+{
+    return float64_add(a, b, &env->fp_status);
+}
+
+float64 HELPER(sub_f64)(CPUM68KState *env, float64 a, float64 b)
+{
+    return float64_sub(a, b, &env->fp_status);
+}
+
+float64 HELPER(mul_f64)(CPUM68KState *env, float64 a, float64 b)
+{
+    return float64_mul(a, b, &env->fp_status);
+}
+
+float64 HELPER(div_f64)(CPUM68KState *env, float64 a, float64 b)
+{
+    return float64_div(a, b, &env->fp_status);
+}
+
+float64 HELPER(sub_cmp_f64)(CPUM68KState *env, float64 a, float64 b)
+{
+    /* ??? This may incorrectly raise exceptions.  */
+    /* ??? Should flush denormals to zero.  */
+    float64 res;
+    res = float64_sub(a, b, &env->fp_status);
+    if (float64_is_quiet_nan(res, &env->fp_status)) {
+        /* +/-inf compares equal against itself, but sub returns nan.  */
+        if (!float64_is_quiet_nan(a, &env->fp_status)
+            && !float64_is_quiet_nan(b, &env->fp_status)) {
+            res = float64_zero;
+            if (float64_lt_quiet(a, res, &env->fp_status)) {
+                res = float64_chs(res);
+            }
+        }
+    }
+    return res;
+}
+
+uint32_t HELPER(compare_f64)(CPUM68KState *env, float64 val)
+{
+    return float64_compare_quiet(val, float64_zero, &env->fp_status);
+}
diff --git a/target/m68k/helper.c b/target/m68k/helper.c
index f750d3d..5ca9911 100644
--- a/target/m68k/helper.c
+++ b/target/m68k/helper.c
@@ -284,94 +284,6 @@ void HELPER(set_sr)(CPUM68KState *env, uint32_t val)
     m68k_switch_sp(env);
 }
 
-/* FPU helpers.  */
-uint32_t HELPER(f64_to_i32)(CPUM68KState *env, float64 val)
-{
-    return float64_to_int32(val, &env->fp_status);
-}
-
-float32 HELPER(f64_to_f32)(CPUM68KState *env, float64 val)
-{
-    return float64_to_float32(val, &env->fp_status);
-}
-
-float64 HELPER(i32_to_f64)(CPUM68KState *env, uint32_t val)
-{
-    return int32_to_float64(val, &env->fp_status);
-}
-
-float64 HELPER(f32_to_f64)(CPUM68KState *env, float32 val)
-{
-    return float32_to_float64(val, &env->fp_status);
-}
-
-float64 HELPER(iround_f64)(CPUM68KState *env, float64 val)
-{
-    return float64_round_to_int(val, &env->fp_status);
-}
-
-float64 HELPER(itrunc_f64)(CPUM68KState *env, float64 val)
-{
-    return float64_trunc_to_int(val, &env->fp_status);
-}
-
-float64 HELPER(sqrt_f64)(CPUM68KState *env, float64 val)
-{
-    return float64_sqrt(val, &env->fp_status);
-}
-
-float64 HELPER(abs_f64)(float64 val)
-{
-    return float64_abs(val);
-}
-
-float64 HELPER(chs_f64)(float64 val)
-{
-    return float64_chs(val);
-}
-
-float64 HELPER(add_f64)(CPUM68KState *env, float64 a, float64 b)
-{
-    return float64_add(a, b, &env->fp_status);
-}
-
-float64 HELPER(sub_f64)(CPUM68KState *env, float64 a, float64 b)
-{
-    return float64_sub(a, b, &env->fp_status);
-}
-
-float64 HELPER(mul_f64)(CPUM68KState *env, float64 a, float64 b)
-{
-    return float64_mul(a, b, &env->fp_status);
-}
-
-float64 HELPER(div_f64)(CPUM68KState *env, float64 a, float64 b)
-{
-    return float64_div(a, b, &env->fp_status);
-}
-
-float64 HELPER(sub_cmp_f64)(CPUM68KState *env, float64 a, float64 b)
-{
-    /* ??? This may incorrectly raise exceptions.  */
-    /* ??? Should flush denormals to zero.  */
-    float64 res;
-    res = float64_sub(a, b, &env->fp_status);
-    if (float64_is_quiet_nan(res, &env->fp_status)) {
-        /* +/-inf compares equal against itself, but sub returns nan.  */
-        if (!float64_is_quiet_nan(a, &env->fp_status)
-            && !float64_is_quiet_nan(b, &env->fp_status)) {
-            res = float64_zero;
-            if (float64_lt_quiet(a, res, &env->fp_status))
-                res = float64_chs(res);
-        }
-    }
-    return res;
-}
-
-uint32_t HELPER(compare_f64)(CPUM68KState *env, float64 val)
-{
-    return float64_compare_quiet(val, float64_zero, &env->fp_status);
-}
 
 /* MAC unit.  */
 /* FIXME: The MAC unit implementation is a bit of a mess.  Some helpers
-- 
2.9.4

[Qemu-devel] [PULL 4/4] target-m68k: define ext_opsize

[Laurent Vivier]

Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Message-Id: <20170611231633.32582-4-laurent@vivier.eu>
---
 target/m68k/translate.c | 43 ++++++++++++++++++++++++-------------------
 1 file changed, 24 insertions(+), 19 deletions(-)

diff --git a/target/m68k/translate.c b/target/m68k/translate.c
index 52653f6..dfecfb6 100644
--- a/target/m68k/translate.c
+++ b/target/m68k/translate.c
@@ -669,6 +669,21 @@ static inline int insn_opsize(int insn)
     }
 }
 
+static inline int ext_opsize(int ext, int pos)
+{
+    switch ((ext >> pos) & 7) {
+    case 0: return OS_LONG;
+    case 1: return OS_SINGLE;
+    case 2: return OS_EXTENDED;
+    case 3: return OS_PACKED;
+    case 4: return OS_WORD;
+    case 5: return OS_DOUBLE;
+    case 6: return OS_BYTE;
+    default:
+        g_assert_not_reached();
+    }
+}
+
 /* Assign value to a register.  If the width is less than the register width
    only the low part of the register is set.  */
 static void gen_partset_reg(int opsize, TCGv reg, TCGv val)
@@ -4111,20 +4126,19 @@ DISAS_INSN(fpu)
         tmp32 = tcg_temp_new_i32();
         /* fmove */
         /* ??? TODO: Proper behavior on overflow.  */
-        switch ((ext >> 10) & 7) {
-        case 0:
-            opsize = OS_LONG;
+
+        opsize = ext_opsize(ext, 10);
+        switch (opsize) {
+        case OS_LONG:
             gen_helper_f64_to_i32(tmp32, cpu_env, src);
             break;
-        case 1:
-            opsize = OS_SINGLE;
+        case OS_SINGLE:
             gen_helper_f64_to_f32(tmp32, cpu_env, src);
             break;
-        case 4:
-            opsize = OS_WORD;
+        case OS_WORD:
             gen_helper_f64_to_i32(tmp32, cpu_env, src);
             break;
-        case 5: /* OS_DOUBLE */
+        case OS_DOUBLE:
             tcg_gen_mov_i32(tmp32, AREG(insn, 0));
             switch ((insn >> 3) & 7) {
             case 2:
@@ -4153,8 +4167,7 @@ DISAS_INSN(fpu)
             }
             tcg_temp_free_i32(tmp32);
             return;
-        case 6:
-            opsize = OS_BYTE;
+        case OS_BYTE:
             gen_helper_f64_to_i32(tmp32, cpu_env, src);
             break;
         default:
@@ -4227,15 +4240,7 @@ DISAS_INSN(fpu)
     }
     if (ext & (1 << 14)) {
         /* Source effective address.  */
-        switch ((ext >> 10) & 7) {
-        case 0: opsize = OS_LONG; break;
-        case 1: opsize = OS_SINGLE; break;
-        case 4: opsize = OS_WORD; break;
-        case 5: opsize = OS_DOUBLE; break;
-        case 6: opsize = OS_BYTE; break;
-        default:
-            goto undef;
-        }
+        opsize = ext_opsize(ext, 10);
         if (opsize == OS_DOUBLE) {
             tmp32 = tcg_temp_new_i32();
             tcg_gen_mov_i32(tmp32, AREG(insn, 0));
-- 
2.9.4

Re: [Qemu-devel] [PULL 0/4] M68k for 2.10 patches

[Peter Maydell]

On 15 June 2017 at 09:17, Laurent Vivier <laurent@vivier.eu> wrote:
> The following changes since commit 3f0602927b120a480b35dcf58cf6f95435b3ae91:
>
>   Merge remote-tracking branch 'remotes/pmaydell/tags/pull-target-arm-20170613' into staging (2017-06-13 15:49:07 +0100)
>
> are available in the git repository at:
>
>   git://github.com/vivier/qemu-m68k.git tags/m68k-for-2.10-pull-request
>
> for you to fetch changes up to 69e698220f68a17ce9584b068f68ed09e527a6ad:
>
>   target-m68k: define ext_opsize (2017-06-15 09:16:38 +0200)
>
> ----------------------------------------------------------------
>
> ----------------------------------------------------------------
>
> Laurent Vivier (4):
>   target/m68k: fix V flag for CC_OP_SUBx
>   softfloat: define 680x0 specific values
>   target-m68k: move FPU helpers to fpu_helper.c
>   target-m68k: define ext_opsize
Applied, thanks.

-- PMM