Following Uros' suggestion, this patch adds support for AVX512VL's vpro[lr][dq] instructions to the recently added scalar-to-vector (STV) enhancements to handle DImode and SImode rotations by a constant.
For the test cases: unsigned long long rot1(unsigned long long x) { return (x>>1) | (x<<63); } void mem1(unsigned long long *p) { *p = rot1(*p); } with -m32 -O2 -mavx512vl, we currently generate: rot1: movl 4(%esp), %eax movl 8(%esp), %edx movl %eax, %ecx shrdl $1, %edx, %eax shrdl $1, %ecx, %edx ret mem1: movl 4(%esp), %eax vmovq (%eax), %xmm0 vpshufd $20, %xmm0, %xmm0 vpsrlq $1, %xmm0, %xmm0 vpshufd $136, %xmm0, %xmm0 vmovq %xmm0, (%eax) ret with this patch, we now generate: rot1: vmovq 4(%esp), %xmm0 vprorq $1, %xmm0, %xmm0 vmovd %xmm0, %eax vpextrd $1, %xmm0, %edx ret mem1: movl 4(%esp), %eax vmovq (%eax), %xmm0 vprorq $1, %xmm0, %xmm0 vmovq %xmm0, (%eax) ret This patch has been tested on x86_64-pc-linux-gnu (cascadelake which has avx512) with make bootstrap and make -k check, both with and without --target_board=unix{-m32} with no new failures. Ok for mainline? 2023-07-09 Roger Sayle <ro...@nextmovesoftware.com> gcc/ChangeLog * config/i386/i386-features.cc (compute_convert_gain): Tweak gains/costs for ROTATE/ROTATERT by integer constant on AVX512VL. (general_scalar_chain::convert_rotate): On TARGET_AVX512F generate avx512vl_rolv2di or avx412vl_rolv4si when appropriate. gcc/testsuite/ChangeLog * gcc.target/i386/avx512vl-stv-rotatedi-1.c: New test case. Cheers, Roger --
diff --git a/gcc/config/i386/i386-features.cc b/gcc/config/i386/i386-features.cc index 2e751d1..4d69251 100644 --- a/gcc/config/i386/i386-features.cc +++ b/gcc/config/i386/i386-features.cc @@ -585,7 +585,9 @@ general_scalar_chain::compute_convert_gain () case ROTATE: case ROTATERT: igain += m * ix86_cost->shift_const; - if (smode == DImode) + if (TARGET_AVX512F) + igain -= ix86_cost->sse_op; + else if (smode == DImode) { int bits = INTVAL (XEXP (src, 1)); if ((bits & 0x0f) == 0) @@ -1225,6 +1227,8 @@ general_scalar_chain::convert_rotate (enum rtx_code code, rtx op0, rtx op1, emit_insn_before (pat, insn); result = gen_lowpart (V2DImode, tmp1); } + else if (TARGET_AVX512F) + result = simplify_gen_binary (code, V2DImode, op0, op1); else if (bits == 16 || bits == 48) { rtx tmp1 = gen_reg_rtx (V8HImode); @@ -1269,6 +1273,8 @@ general_scalar_chain::convert_rotate (enum rtx_code code, rtx op0, rtx op1, emit_insn_before (pat, insn); result = gen_lowpart (V4SImode, tmp1); } + else if (TARGET_AVX512F) + result = simplify_gen_binary (code, V4SImode, op0, op1); else { if (code == ROTATE) diff --git a/gcc/testsuite/gcc.target/i386/avx512vl-stv-rotatedi-1.c b/gcc/testsuite/gcc.target/i386/avx512vl-stv-rotatedi-1.c new file mode 100644 index 0000000..2f0ead8 --- /dev/null +++ b/gcc/testsuite/gcc.target/i386/avx512vl-stv-rotatedi-1.c @@ -0,0 +1,35 @@ +/* { dg-do compile { target ia32 } } */ +/* { dg-options "-O2 -mavx512vl" } */ + +unsigned long long rot1(unsigned long long x) { return (x>>1) | (x<<63); } +unsigned long long rot2(unsigned long long x) { return (x>>2) | (x<<62); } +unsigned long long rot3(unsigned long long x) { return (x>>3) | (x<<61); } +unsigned long long rot4(unsigned long long x) { return (x>>4) | (x<<60); } +unsigned long long rot5(unsigned long long x) { return (x>>5) | (x<<59); } +unsigned long long rot6(unsigned long long x) { return (x>>6) | (x<<58); } +unsigned long long rot7(unsigned long long x) { return (x>>7) | (x<<57); } +unsigned long long rot8(unsigned long long x) { return (x>>8) | (x<<56); } +unsigned long long rot9(unsigned long long x) { return (x>>9) | (x<<55); } +unsigned long long rot10(unsigned long long x) { return (x>>10) | (x<<54); } +unsigned long long rot15(unsigned long long x) { return (x>>15) | (x<<49); } +unsigned long long rot16(unsigned long long x) { return (x>>16) | (x<<48); } +unsigned long long rot17(unsigned long long x) { return (x>>17) | (x<<47); } +unsigned long long rot20(unsigned long long x) { return (x>>20) | (x<<44); } +unsigned long long rot24(unsigned long long x) { return (x>>24) | (x<<40); } +unsigned long long rot30(unsigned long long x) { return (x>>30) | (x<<34); } +unsigned long long rot31(unsigned long long x) { return (x>>31) | (x<<33); } +unsigned long long rot32(unsigned long long x) { return (x>>32) | (x<<32); } +unsigned long long rot33(unsigned long long x) { return (x>>33) | (x<<31); } +unsigned long long rot34(unsigned long long x) { return (x>>34) | (x<<30); } +unsigned long long rot40(unsigned long long x) { return (x>>40) | (x<<24); } +unsigned long long rot42(unsigned long long x) { return (x>>42) | (x<<22); } +unsigned long long rot48(unsigned long long x) { return (x>>48) | (x<<16); } +unsigned long long rot50(unsigned long long x) { return (x>>50) | (x<<14); } +unsigned long long rot56(unsigned long long x) { return (x>>56) | (x<<8); } +unsigned long long rot58(unsigned long long x) { return (x>>58) | (x<<6); } +unsigned long long rot60(unsigned long long x) { return (x>>60) | (x<<4); } +unsigned long long rot61(unsigned long long x) { return (x>>61) | (x<<3); } +unsigned long long rot62(unsigned long long x) { return (x>>62) | (x<<2); } +unsigned long long rot63(unsigned long long x) { return (x>>63) | (x<<1); } + +/* { dg-final { scan-assembler-times "vpro\[lr\]q" 29 } } */