All of lore.kernel.org
 help / color / mirror / Atom feed
From: Peter Maydell <peter.maydell@linaro.org>
To: qemu-devel@nongnu.org
Subject: [PULL 093/114] target/arm: Implement SVE2 TBL, TBX
Date: Tue, 25 May 2021 16:03:03 +0100	[thread overview]
Message-ID: <20210525150324.32370-94-peter.maydell@linaro.org> (raw)
In-Reply-To: <20210525150324.32370-1-peter.maydell@linaro.org>

From: Stephen Long <steplong@quicinc.com>

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Stephen Long <steplong@quicinc.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210525010358.152808-72-richard.henderson@linaro.org
Message-Id: <20200428144352.9275-1-steplong@quicinc.com>
[rth: rearrange the macros a little and rebase]
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
 target/arm/helper-sve.h    | 10 +++++
 target/arm/sve.decode      |  5 +++
 target/arm/sve_helper.c    | 90 ++++++++++++++++++++++++++++++--------
 target/arm/translate-sve.c | 33 ++++++++++++++
 4 files changed, 119 insertions(+), 19 deletions(-)

diff --git a/target/arm/helper-sve.h b/target/arm/helper-sve.h
index efc9a7ccf18..cdff155ead4 100644
--- a/target/arm/helper-sve.h
+++ b/target/arm/helper-sve.h
@@ -661,6 +661,16 @@ DEF_HELPER_FLAGS_4(sve_tbl_h, TCG_CALL_NO_RWG, void, ptr, ptr, ptr, i32)
 DEF_HELPER_FLAGS_4(sve_tbl_s, TCG_CALL_NO_RWG, void, ptr, ptr, ptr, i32)
 DEF_HELPER_FLAGS_4(sve_tbl_d, TCG_CALL_NO_RWG, void, ptr, ptr, ptr, i32)
 
+DEF_HELPER_FLAGS_5(sve2_tbl_b, TCG_CALL_NO_RWG, void, ptr, ptr, ptr, ptr, i32)
+DEF_HELPER_FLAGS_5(sve2_tbl_h, TCG_CALL_NO_RWG, void, ptr, ptr, ptr, ptr, i32)
+DEF_HELPER_FLAGS_5(sve2_tbl_s, TCG_CALL_NO_RWG, void, ptr, ptr, ptr, ptr, i32)
+DEF_HELPER_FLAGS_5(sve2_tbl_d, TCG_CALL_NO_RWG, void, ptr, ptr, ptr, ptr, i32)
+
+DEF_HELPER_FLAGS_4(sve2_tbx_b, TCG_CALL_NO_RWG, void, ptr, ptr, ptr, i32)
+DEF_HELPER_FLAGS_4(sve2_tbx_h, TCG_CALL_NO_RWG, void, ptr, ptr, ptr, i32)
+DEF_HELPER_FLAGS_4(sve2_tbx_s, TCG_CALL_NO_RWG, void, ptr, ptr, ptr, i32)
+DEF_HELPER_FLAGS_4(sve2_tbx_d, TCG_CALL_NO_RWG, void, ptr, ptr, ptr, i32)
+
 DEF_HELPER_FLAGS_3(sve_sunpk_h, TCG_CALL_NO_RWG, void, ptr, ptr, i32)
 DEF_HELPER_FLAGS_3(sve_sunpk_s, TCG_CALL_NO_RWG, void, ptr, ptr, i32)
 DEF_HELPER_FLAGS_3(sve_sunpk_d, TCG_CALL_NO_RWG, void, ptr, ptr, i32)
diff --git a/target/arm/sve.decode b/target/arm/sve.decode
index 051a6399ac0..fdeb7b106b3 100644
--- a/target/arm/sve.decode
+++ b/target/arm/sve.decode
@@ -558,6 +558,11 @@ TBL             00000101 .. 1 ..... 001100 ..... .....          @rd_rn_rm
 # SVE unpack vector elements
 UNPK            00000101 esz:2 1100 u:1 h:1 001110 rn:5 rd:5
 
+# SVE2 Table Lookup (three sources)
+
+TBL_sve2        00000101 .. 1 ..... 001010 ..... .....          @rd_rn_rm
+TBX             00000101 .. 1 ..... 001011 ..... .....          @rd_rn_rm
+
 ### SVE Permute - Predicates Group
 
 # SVE permute predicate elements
diff --git a/target/arm/sve_helper.c b/target/arm/sve_helper.c
index f9c20612602..4b05e2e4276 100644
--- a/target/arm/sve_helper.c
+++ b/target/arm/sve_helper.c
@@ -3069,28 +3069,80 @@ void HELPER(sve_rev_d)(void *vd, void *vn, uint32_t desc)
     }
 }
 
-#define DO_TBL(NAME, TYPE, H) \
-void HELPER(NAME)(void *vd, void *vn, void *vm, uint32_t desc) \
-{                                                              \
-    intptr_t i, opr_sz = simd_oprsz(desc);                     \
-    uintptr_t elem = opr_sz / sizeof(TYPE);                    \
-    TYPE *d = vd, *n = vn, *m = vm;                            \
-    ARMVectorReg tmp;                                          \
-    if (unlikely(vd == vn)) {                                  \
-        n = memcpy(&tmp, vn, opr_sz);                          \
-    }                                                          \
-    for (i = 0; i < elem; i++) {                               \
-        TYPE j = m[H(i)];                                      \
-        d[H(i)] = j < elem ? n[H(j)] : 0;                      \
-    }                                                          \
+typedef void tb_impl_fn(void *, void *, void *, void *, uintptr_t, bool);
+
+static inline void do_tbl1(void *vd, void *vn, void *vm, uint32_t desc,
+                           bool is_tbx, tb_impl_fn *fn)
+{
+    ARMVectorReg scratch;
+    uintptr_t oprsz = simd_oprsz(desc);
+
+    if (unlikely(vd == vn)) {
+        vn = memcpy(&scratch, vn, oprsz);
+    }
+
+    fn(vd, vn, NULL, vm, oprsz, is_tbx);
 }
 
-DO_TBL(sve_tbl_b, uint8_t, H1)
-DO_TBL(sve_tbl_h, uint16_t, H2)
-DO_TBL(sve_tbl_s, uint32_t, H4)
-DO_TBL(sve_tbl_d, uint64_t, )
+static inline void do_tbl2(void *vd, void *vn0, void *vn1, void *vm,
+                           uint32_t desc, bool is_tbx, tb_impl_fn *fn)
+{
+    ARMVectorReg scratch;
+    uintptr_t oprsz = simd_oprsz(desc);
 
-#undef TBL
+    if (unlikely(vd == vn0)) {
+        vn0 = memcpy(&scratch, vn0, oprsz);
+        if (vd == vn1) {
+            vn1 = vn0;
+        }
+    } else if (unlikely(vd == vn1)) {
+        vn1 = memcpy(&scratch, vn1, oprsz);
+    }
+
+    fn(vd, vn0, vn1, vm, oprsz, is_tbx);
+}
+
+#define DO_TB(SUFF, TYPE, H)                                            \
+static inline void do_tb_##SUFF(void *vd, void *vt0, void *vt1,         \
+                                void *vm, uintptr_t oprsz, bool is_tbx) \
+{                                                                       \
+    TYPE *d = vd, *tbl0 = vt0, *tbl1 = vt1, *indexes = vm;              \
+    uintptr_t i, nelem = oprsz / sizeof(TYPE);                          \
+    for (i = 0; i < nelem; ++i) {                                       \
+        TYPE index = indexes[H1(i)], val = 0;                           \
+        if (index < nelem) {                                            \
+            val = tbl0[H(index)];                                       \
+        } else {                                                        \
+            index -= nelem;                                             \
+            if (tbl1 && index < nelem) {                                \
+                val = tbl1[H(index)];                                   \
+            } else if (is_tbx) {                                        \
+                continue;                                               \
+            }                                                           \
+        }                                                               \
+        d[H(i)] = val;                                                  \
+    }                                                                   \
+}                                                                       \
+void HELPER(sve_tbl_##SUFF)(void *vd, void *vn, void *vm, uint32_t desc) \
+{                                                                       \
+    do_tbl1(vd, vn, vm, desc, false, do_tb_##SUFF);                     \
+}                                                                       \
+void HELPER(sve2_tbl_##SUFF)(void *vd, void *vn0, void *vn1,            \
+                             void *vm, uint32_t desc)                   \
+{                                                                       \
+    do_tbl2(vd, vn0, vn1, vm, desc, false, do_tb_##SUFF);               \
+}                                                                       \
+void HELPER(sve2_tbx_##SUFF)(void *vd, void *vn, void *vm, uint32_t desc) \
+{                                                                       \
+    do_tbl1(vd, vn, vm, desc, true, do_tb_##SUFF);                      \
+}
+
+DO_TB(b, uint8_t, H1)
+DO_TB(h, uint16_t, H2)
+DO_TB(s, uint32_t, H4)
+DO_TB(d, uint64_t,   )
+
+#undef DO_TB
 
 #define DO_UNPK(NAME, TYPED, TYPES, HD, HS) \
 void HELPER(NAME)(void *vd, void *vn, uint32_t desc)           \
diff --git a/target/arm/translate-sve.c b/target/arm/translate-sve.c
index 2136a410945..9a6f7c87c1e 100644
--- a/target/arm/translate-sve.c
+++ b/target/arm/translate-sve.c
@@ -2417,6 +2417,39 @@ static bool trans_TBL(DisasContext *s, arg_rrr_esz *a)
     return true;
 }
 
+static bool trans_TBL_sve2(DisasContext *s, arg_rrr_esz *a)
+{
+    static gen_helper_gvec_4 * const fns[4] = {
+        gen_helper_sve2_tbl_b, gen_helper_sve2_tbl_h,
+        gen_helper_sve2_tbl_s, gen_helper_sve2_tbl_d
+    };
+
+    if (!dc_isar_feature(aa64_sve2, s)) {
+        return false;
+    }
+    if (sve_access_check(s)) {
+        gen_gvec_ool_zzzz(s, fns[a->esz], a->rd, a->rn,
+                          (a->rn + 1) % 32, a->rm, 0);
+    }
+    return true;
+}
+
+static bool trans_TBX(DisasContext *s, arg_rrr_esz *a)
+{
+    static gen_helper_gvec_3 * const fns[4] = {
+        gen_helper_sve2_tbx_b, gen_helper_sve2_tbx_h,
+        gen_helper_sve2_tbx_s, gen_helper_sve2_tbx_d
+    };
+
+    if (!dc_isar_feature(aa64_sve2, s)) {
+        return false;
+    }
+    if (sve_access_check(s)) {
+        gen_gvec_ool_zzz(s, fns[a->esz], a->rd, a->rn, a->rm, 0);
+    }
+    return true;
+}
+
 static bool trans_UNPK(DisasContext *s, arg_UNPK *a)
 {
     static gen_helper_gvec_2 * const fns[4][2] = {
-- 
2.20.1



  parent reply	other threads:[~2021-05-25 16:03 UTC|newest]

Thread overview: 96+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-05-25 15:01 [PULL 000/114] target-arm queue Peter Maydell
2021-05-25 15:01 ` [PULL 001/114] hw/arm/smmuv3: Another range invalidation fix Peter Maydell
2021-05-25 15:01 ` [PULL 002/114] hw/intc/arm_gicv3_cpuif: Fix EOIR write access check logic Peter Maydell
2021-05-25 15:01 ` [PULL 003/114] hw/arm/mps2-tz: Don't duplicate modelling of SRAM in AN524 Peter Maydell
2021-05-25 15:01 ` [PULL 004/114] hw/arm/mps2-tz: Make SRAM_ADDR_WIDTH board-specific Peter Maydell
2021-05-25 15:01 ` [PULL 005/114] hw/arm/armsse.c: Correct modelling of SSE-300 internal SRAMs Peter Maydell
2021-05-25 15:01 ` [PULL 006/114] hw/arm/armsse: Convert armsse_realize() to use ERRP_GUARD Peter Maydell
2021-05-25 15:01 ` [PULL 007/114] hw/arm/mps2-tz: Allow board to specify a boot RAM size Peter Maydell
2021-05-25 15:01 ` [PULL 008/114] hw/arm: Model TCMs in the SSE-300, not the AN547 Peter Maydell
2021-05-25 15:01 ` [PULL 009/114] target/arm: Use correct SP in M-profile exception return Peter Maydell
2021-05-25 15:01 ` [PULL 010/114] accel/tcg: Replace g_new() + memcpy() by g_memdup() Peter Maydell
2021-05-25 15:01 ` [PULL 011/114] accel/tcg: Pass length argument to tlb_flush_range_locked() Peter Maydell
2021-05-25 15:01 ` [PULL 012/114] accel/tlb: Rename TLBFlushPageBitsByMMUIdxData -> TLBFlushRangeData Peter Maydell
2021-05-25 15:01 ` [PULL 013/114] accel/tcg: Remove {encode,decode}_pbm_to_runon Peter Maydell
2021-05-25 15:01 ` [PULL 014/114] accel/tcg: Add tlb_flush_range_by_mmuidx() Peter Maydell
2021-05-25 15:01 ` [PULL 015/114] accel/tcg: Add tlb_flush_range_by_mmuidx_all_cpus() Peter Maydell
2021-05-25 15:01 ` [PULL 016/114] accel/tlb: Add tlb_flush_range_by_mmuidx_all_cpus_synced() Peter Maydell
2021-05-25 15:01 ` [PULL 017/114] accel/tcg: Rename tlb_flush_page_bits -> range]_by_mmuidx_async_0 Peter Maydell
2021-05-25 15:01 ` [PULL 018/114] accel/tlb: Rename tlb_flush_[page_bits > range]_by_mmuidx_async_[2 > 1] Peter Maydell
2021-05-25 15:01 ` [PULL 019/114] target/arm: Add support for FEAT_TLBIRANGE Peter Maydell
2021-05-25 15:01 ` [PULL 020/114] target/arm: Add support for FEAT_TLBIOS Peter Maydell
2021-05-25 15:01 ` [PULL 021/114] target/arm: set ID_AA64ISAR0.TLB to 2 for max AARCH64 CPU type Peter Maydell
2021-05-25 15:01 ` [PULL 022/114] disas/libvixl: Protect C system header for C++ compiler Peter Maydell
2021-05-25 15:01 ` [PULL 023/114] target/arm: Add ID_AA64ZFR0 fields and isar_feature_aa64_sve2 Peter Maydell
2021-05-25 15:01 ` [PULL 024/114] target/arm: Implement SVE2 Integer Multiply - Unpredicated Peter Maydell
2021-05-25 15:01 ` [PULL 025/114] target/arm: Implement SVE2 integer pairwise add and accumulate long Peter Maydell
2021-05-25 15:01 ` [PULL 026/114] target/arm: Implement SVE2 integer unary operations (predicated) Peter Maydell
2021-05-25 15:01 ` [PULL 027/114] target/arm: Split out saturating/rounding shifts from neon Peter Maydell
2021-05-25 15:01 ` [PULL 028/114] target/arm: Implement SVE2 saturating/rounding bitwise shift left (predicated) Peter Maydell
2021-05-25 15:01 ` [PULL 029/114] target/arm: Implement SVE2 integer halving add/subtract (predicated) Peter Maydell
2021-05-25 15:02 ` [PULL 030/114] target/arm: Implement SVE2 integer pairwise arithmetic Peter Maydell
2021-05-25 15:02 ` [PULL 031/114] target/arm: Implement SVE2 saturating add/subtract (predicated) Peter Maydell
2021-05-25 15:02 ` [PULL 032/114] target/arm: Implement SVE2 integer add/subtract long Peter Maydell
2021-05-25 15:02 ` [PULL 033/114] target/arm: Implement SVE2 integer add/subtract interleaved long Peter Maydell
2021-05-25 15:02 ` [PULL 034/114] target/arm: Implement SVE2 integer add/subtract wide Peter Maydell
2021-05-25 15:02 ` [PULL 035/114] target/arm: Implement SVE2 integer multiply long Peter Maydell
2021-05-25 15:02 ` [PULL 036/114] target/arm: Implement SVE2 PMULLB, PMULLT Peter Maydell
2021-05-25 15:02 ` [PULL 037/114] target/arm: Implement SVE2 bitwise shift left long Peter Maydell
2021-05-25 15:02 ` [PULL 038/114] target/arm: Implement SVE2 bitwise exclusive-or interleaved Peter Maydell
2021-05-25 15:02 ` [PULL 039/114] target/arm: Implement SVE2 bitwise permute Peter Maydell
2021-05-25 15:02 ` [PULL 040/114] target/arm: Implement SVE2 complex integer add Peter Maydell
2021-05-25 15:02 ` [PULL 041/114] target/arm: Implement SVE2 integer absolute difference and accumulate long Peter Maydell
2021-05-25 15:02 ` [PULL 042/114] target/arm: Implement SVE2 integer add/subtract long with carry Peter Maydell
2021-05-25 15:02 ` [PULL 043/114] target/arm: Implement SVE2 bitwise shift right and accumulate Peter Maydell
2021-05-25 15:02 ` [PULL 044/114] target/arm: Implement SVE2 bitwise shift and insert Peter Maydell
2021-05-25 15:02 ` [PULL 045/114] target/arm: Implement SVE2 integer absolute difference and accumulate Peter Maydell
2021-05-25 15:02 ` [PULL 046/114] target/arm: Implement SVE2 saturating extract narrow Peter Maydell
2021-05-25 15:02 ` [PULL 047/114] target/arm: Implement SVE2 floating-point pairwise Peter Maydell
2021-05-25 15:02 ` [PULL 048/114] target/arm: Implement SVE2 SHRN, RSHRN Peter Maydell
2021-05-25 15:02 ` [PULL 049/114] target/arm: Implement SVE2 SQSHRUN, SQRSHRUN Peter Maydell
2021-05-25 15:02 ` [PULL 050/114] target/arm: Implement SVE2 UQSHRN, UQRSHRN Peter Maydell
2021-05-25 15:02 ` [PULL 051/114] target/arm: Implement SVE2 SQSHRN, SQRSHRN Peter Maydell
2021-05-25 15:02 ` [PULL 052/114] target/arm: Implement SVE2 WHILEGT, WHILEGE, WHILEHI, WHILEHS Peter Maydell
2021-05-25 15:02 ` [PULL 053/114] target/arm: Implement SVE2 WHILERW, WHILEWR Peter Maydell
2021-05-25 15:02 ` [PULL 054/114] target/arm: Implement SVE2 bitwise ternary operations Peter Maydell
2021-05-25 15:02 ` [PULL 055/114] target/arm: Implement SVE2 MATCH, NMATCH Peter Maydell
2021-05-25 15:02 ` [PULL 056/114] target/arm: Implement SVE2 saturating multiply-add long Peter Maydell
2021-05-25 15:02 ` [PULL 057/114] target/arm: Implement SVE2 saturating multiply-add high Peter Maydell
2021-05-25 15:02 ` [PULL 058/114] target/arm: Implement SVE2 integer multiply-add long Peter Maydell
2021-05-25 15:02 ` [PULL 059/114] target/arm: Implement SVE2 complex integer multiply-add Peter Maydell
2021-05-25 15:02 ` [PULL 060/114] target/arm: Implement SVE2 ADDHNB, ADDHNT Peter Maydell
2021-05-25 15:02 ` [PULL 061/114] target/arm: Implement SVE2 RADDHNB, RADDHNT Peter Maydell
2021-05-25 15:02 ` [PULL 062/114] target/arm: Implement SVE2 SUBHNB, SUBHNT Peter Maydell
2021-05-25 15:02 ` [PULL 063/114] target/arm: Implement SVE2 RSUBHNB, RSUBHNT Peter Maydell
2021-05-25 15:02 ` [PULL 064/114] target/arm: Implement SVE2 HISTCNT, HISTSEG Peter Maydell
2021-05-25 15:02 ` [PULL 065/114] target/arm: Implement SVE2 XAR Peter Maydell
2021-05-25 15:02 ` [PULL 066/114] target/arm: Implement SVE2 scatter store insns Peter Maydell
2021-05-25 15:02 ` [PULL 067/114] target/arm: Implement SVE2 gather load insns Peter Maydell
2021-05-25 15:02 ` [PULL 068/114] target/arm: Implement SVE2 FMMLA Peter Maydell
2021-05-25 15:02 ` [PULL 069/114] target/arm: Implement SVE2 SPLICE, EXT Peter Maydell
2021-05-25 15:02 ` [PULL 070/114] target/arm: Use correct output type for gvec_sdot_*_b Peter Maydell
2021-05-25 15:02 ` [PULL 071/114] target/arm: Pass separate addend to {U, S}DOT helpers Peter Maydell
2021-05-25 15:02 ` [PULL 072/114] target/arm: Pass separate addend to FCMLA helpers Peter Maydell
2021-05-25 15:02 ` [PULL 073/114] target/arm: Split out formats for 2 vectors + 1 index Peter Maydell
2021-05-25 15:02 ` [PULL 074/114] target/arm: Split out formats for 3 " Peter Maydell
2021-05-25 15:02 ` [PULL 075/114] target/arm: Implement SVE2 integer multiply (indexed) Peter Maydell
2021-05-25 15:02 ` [PULL 076/114] target/arm: Implement SVE2 integer multiply-add (indexed) Peter Maydell
2021-05-25 15:02 ` [PULL 077/114] target/arm: Implement SVE2 saturating multiply-add high (indexed) Peter Maydell
2021-05-25 15:02 ` [PULL 078/114] target/arm: Implement SVE2 saturating multiply-add (indexed) Peter Maydell
2021-05-25 15:02 ` [PULL 079/114] target/arm: Implement SVE2 saturating multiply (indexed) Peter Maydell
2021-05-25 15:02 ` [PULL 080/114] target/arm: Implement SVE2 signed saturating doubling multiply high Peter Maydell
2021-05-25 15:02 ` [PULL 081/114] target/arm: Implement SVE2 saturating multiply high (indexed) Peter Maydell
2021-05-25 15:02 ` [PULL 082/114] target/arm: Implement SVE2 multiply-add long (indexed) Peter Maydell
2021-05-25 15:02 ` [PULL 083/114] target/arm: Implement SVE2 integer multiply " Peter Maydell
2021-05-25 15:02 ` [PULL 084/114] target/arm: Implement SVE2 complex integer multiply-add (indexed) Peter Maydell
2021-05-25 15:02 ` [PULL 085/114] target/arm: Implement SVE2 complex integer dot product Peter Maydell
2021-05-25 15:02 ` [PULL 086/114] target/arm: Macroize helper_gvec_{s,u}dot_{b,h} Peter Maydell
2021-05-25 15:02 ` [PULL 087/114] target/arm: Macroize helper_gvec_{s,u}dot_idx_{b,h} Peter Maydell
2021-05-25 15:02 ` [PULL 088/114] target/arm: Implement SVE mixed sign dot product (indexed) Peter Maydell
2021-05-25 15:02 ` [PULL 089/114] target/arm: Implement SVE mixed sign dot product Peter Maydell
2021-05-25 15:03 ` [PULL 090/114] target/arm: Implement SVE2 crypto unary operations Peter Maydell
2021-05-25 15:03 ` [PULL 091/114] target/arm: Implement SVE2 crypto destructive binary operations Peter Maydell
2021-05-25 15:03 ` [PULL 092/114] target/arm: Implement SVE2 crypto constructive " Peter Maydell
2021-05-25 15:03 ` Peter Maydell [this message]
2021-05-25 15:03 ` [PULL 094/114] target/arm: Implement SVE2 FCVTNT Peter Maydell
2021-05-25 16:30 ` [PULL 000/114] target-arm queue Peter Maydell

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20210525150324.32370-94-peter.maydell@linaro.org \
    --to=peter.maydell@linaro.org \
    --cc=qemu-devel@nongnu.org \
    --subject='Re: [PULL 093/114] target/arm: Implement SVE2 TBL, TBX' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.