From 567d06bb357a39ece865cef67ada44124f227e45 Mon Sep 17 00:00:00 2001 From: Yan Simonaytes Date: Tue, 25 Jul 2023 20:43:19 +0300 Subject: [PATCH] i386: eliminate redundant operands of VPTERNLOG As mentioned in PR 110202, GCC may be presented with input where control word of the VPTERNLOG intrinsic implies that some of its operands do not affect the result. In that case, we can eliminate redundant operands of the instruction by substituting any other operand in their place. This removes false dependencies. For instance, instead of (252 = 0xfc = _MM_TERNLOG_A | _MM_TERNLOG_B) vpternlogq $252, %zmm2, %zmm1, %zmm0 emit vpternlogq $252, %zmm0, %zmm1, %zmm0 When VPTERNLOG is invariant w.r.t first and second operands, and the third operand is memory, load memory into the output operand first, i.e. instead of (85 = 0x55 = ~_MM_TERNLOG_C) vpternlogq $85, (%rdi), %zmm1, %zmm0 emit vmovdqa64 (%rdi), %zmm0 vpternlogq $85, %zmm0, %zmm0, %zmm0 gcc/ChangeLog: PR target/110202 * config/i386/i386-protos.h (vpternlog_redundant_operand_mask): Declare. (substitute_vpternlog_operands): Declare. * config/i386/i386.cc (vpternlog_redundant_operand_mask): New helper. (substitute_vpternlog_operands): New function. Use them... * config/i386/sse.md: ... here in new VPTERNLOG define_splits. gcc/testsuite/ChangeLog: PR target/110202 * gcc.target/i386/invariant-ternlog-1.c: New test. * gcc.target/i386/invariant-ternlog-2.c: New test. --- gcc/config/i386/i386-protos.h | 3 ++ gcc/config/i386/i386.cc | 43 +++++++++++++++++++ gcc/config/i386/sse.md | 42 ++++++++++++++++++ .../gcc.target/i386/invariant-ternlog-1.c | 21 +++++++++ .../gcc.target/i386/invariant-ternlog-2.c | 12 ++++++ 5 files changed, 121 insertions(+) create mode 100644 gcc/testsuite/gcc.target/i386/invariant-ternlog-1.c create mode 100644 gcc/testsuite/gcc.target/i386/invariant-ternlog-2.c diff --git a/gcc/config/i386/i386-protos.h b/gcc/config/i386/i386-protos.h index 27fe73ca65c..e547ee64587 100644 --- a/gcc/config/i386/i386-protos.h +++ b/gcc/config/i386/i386-protos.h @@ -70,6 +70,9 @@ extern machine_mode ix86_cc_mode (enum rtx_code, rtx, rtx); extern int avx_vpermilp_parallel (rtx par, machine_mode mode); extern int avx_vperm2f128_parallel (rtx par, machine_mode mode); +extern int vpternlog_redundant_operand_mask (rtx[]); +extern void substitute_vpternlog_operands (rtx[]); + extern bool ix86_expand_strlen (rtx, rtx, rtx, rtx); extern bool ix86_expand_set_or_cpymem (rtx, rtx, rtx, rtx, rtx, rtx, rtx, rtx, rtx, rtx, bool); diff --git a/gcc/config/i386/i386.cc b/gcc/config/i386/i386.cc index eabc70011ea..8cd26eb54fa 100644 --- a/gcc/config/i386/i386.cc +++ b/gcc/config/i386/i386.cc @@ -19451,6 +19451,49 @@ avx_vperm2f128_parallel (rtx par, machine_mode mode) return mask + 1; } +/* Return a mask of VPTERNLOG operands that do not affect output. */ + +int +vpternlog_redundant_operand_mask (rtx *operands) +{ + int mask = 0; + int imm8 = XINT (operands[4], 0); + + if (((imm8 >> 4) & 0x0F) == (imm8 & 0x0F)) + mask |= 1; + if (((imm8 >> 2) & 0x33) == (imm8 & 0x33)) + mask |= 2; + if (((imm8 >> 1) & 0x55) == (imm8 & 0x55)) + mask |= 4; + + return mask; +} + +/* Eliminate false dependencies on operands that do not affect output + by substituting other operands of a VPTERNLOG. */ + +void +substitute_vpternlog_operands (rtx *operands) +{ + int mask = vpternlog_redundant_operand_mask (operands); + + if (mask & 1) /* The first operand is redundant. */ + operands[1] = operands[2]; + + if (mask & 2) /* The second operand is redundant. */ + operands[2] = operands[1]; + + if (mask & 4) /* The third operand is redundant. */ + operands[3] = operands[1]; + else if (REG_P (operands[3])) + { + if (mask & 1) + operands[1] = operands[3]; + if (mask & 2) + operands[2] = operands[3]; + } +} + /* Return a register priority for hard reg REGNO. */ static int ix86_register_priority (int hard_regno) diff --git a/gcc/config/i386/sse.md b/gcc/config/i386/sse.md index f1712b001f9..7e2aa3f995c 100644 --- a/gcc/config/i386/sse.md +++ b/gcc/config/i386/sse.md @@ -12695,6 +12695,48 @@ (symbol_ref " == 64 || TARGET_AVX512VL") (const_string "*")))]) +;; When VPTERNLOG happens to be invariant w.r.t first and second operands, +;; and the third operand is memory, eliminate false dependencies by loading +;; memory into the output operand first. +(define_split + [(set (match_operand:V 0 "register_operand") + (unspec:V + [(match_operand:V 1 "register_operand") + (match_operand:V 2 "register_operand") + (match_operand:V 3 "memory_operand") + (match_operand:SI 4 "const_0_to_255_operand")] + UNSPEC_VTERNLOG))] + "!reload_completed && vpternlog_redundant_operand_mask (operands) == 3" + [(set (match_dup 0) + (match_dup 3)) + (set (match_dup 0) + (unspec:V + [(match_dup 0) + (match_dup 0) + (match_dup 0) + (match_dup 4)] + UNSPEC_VTERNLOG))]) + +;; Eliminate false dependencies when VPTERNLOG is invariant w.r.t any +;; of input operands (except the case handled in the above split). +(define_split + [(set (match_operand:V 0 "register_operand") + (unspec:V + [(match_operand:V 1 "register_operand") + (match_operand:V 2 "register_operand") + (match_operand:V 3 "nonimmediate_operand") + (match_operand:SI 4 "const_0_to_255_operand")] + UNSPEC_VTERNLOG))] + "!reload_completed && vpternlog_redundant_operand_mask (operands) != 0" + [(set (match_dup 0) + (unspec:V + [(match_dup 1) + (match_dup 2) + (match_dup 3) + (match_dup 4)] + UNSPEC_VTERNLOG))] + "substitute_vpternlog_operands (operands);") + ;; There must be lots of other combinations like ;; ;; (any_logic:V diff --git a/gcc/testsuite/gcc.target/i386/invariant-ternlog-1.c b/gcc/testsuite/gcc.target/i386/invariant-ternlog-1.c new file mode 100644 index 00000000000..21051c6bba0 --- /dev/null +++ b/gcc/testsuite/gcc.target/i386/invariant-ternlog-1.c @@ -0,0 +1,21 @@ +/* { dg-do compile } */ +/* { dg-options "-mavx512f -O2" } */ +/* { dg-final { scan-assembler-times "vmovdqa" 4 } } */ +/* { dg-final { scan-assembler-times {vpternlog[^\n\r]*\(%rdx\)} 2 } } */ + +#include + +__m512i f(__m512i* a, __m512i* b, __m512i* c) +{ + return _mm512_ternarylogic_epi64 (a[0], b[0], c[0], ~_MM_TERNLOG_B | ~_MM_TERNLOG_C); +} + +__m512i g(__m512i* a, __m512i* b, __m512i* c) +{ + return _mm512_ternarylogic_epi64 (a[0], b[0], c[0], ~_MM_TERNLOG_A | ~_MM_TERNLOG_C); +} + +__m512i h(__m512i* a, __m512i* b, __m512i* c) +{ + return _mm512_ternarylogic_epi64 (a[0], b[0], c[0], ~_MM_TERNLOG_A | ~_MM_TERNLOG_B); +} diff --git a/gcc/testsuite/gcc.target/i386/invariant-ternlog-2.c b/gcc/testsuite/gcc.target/i386/invariant-ternlog-2.c new file mode 100644 index 00000000000..d70bbb02390 --- /dev/null +++ b/gcc/testsuite/gcc.target/i386/invariant-ternlog-2.c @@ -0,0 +1,12 @@ +/* { dg-do compile } */ +/* { dg-options "-mavx512f -O2" } */ +/* { dg-final { scan-assembler-times "vmovdqa" 1 } } */ +/* { dg-final { scan-assembler "vpternlog.*zmm0.*zmm0.*zmm0" } } */ + +#include + +__m512i f(__m512i* a, __m512i* b, __m512i* c) +{ + return _mm512_ternarylogic_epi64 (a[0], b[0], c[0], ~_MM_TERNLOG_C); +} +