https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89346
--- Comment #4 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by H.J. Lu <h...@gcc.gnu.org>: https://gcc.gnu.org/g:5358e8f5800daa0012fc9d06705d64bbb21fa07b commit r10-7054-g5358e8f5800daa0012fc9d06705d64bbb21fa07b Author: H.J. Lu <hjl.to...@gmail.com> Date: Thu Mar 5 16:45:05 2020 -0800 i386: Properly encode vector registers in vector move On x86, when AVX and AVX512 are enabled, vector move instructions can be encoded with either 2-byte/3-byte VEX (AVX) or 4-byte EVEX (AVX512): 0: c5 f9 6f d1 vmovdqa %xmm1,%xmm2 4: 62 f1 fd 08 6f d1 vmovdqa64 %xmm1,%xmm2 We prefer VEX encoding over EVEX since VEX is shorter. Also AVX512F only supports 512-bit vector moves. AVX512F + AVX512VL supports 128-bit and 256-bit vector moves. xmm16-xmm31 and ymm16-ymm31 are disallowed in 128-bit and 256-bit modes when AVX512VL is disabled. Mode attributes on x86 vector move patterns indicate target preferences of vector move encoding. For scalar register to register move, we can use 512-bit vector move instructions to move 32-bit/64-bit scalar if AVX512VL isn't available. With AVX512F and AVX512VL, we should use VEX encoding for 128-bit/256-bit vector moves if upper 16 vector registers aren't used. This patch adds a function, ix86_output_ssemov, to generate vector moves: 1. If zmm registers are used, use EVEX encoding. 2. If xmm16-xmm31/ymm16-ymm31 registers aren't used, SSE or VEX encoding will be generated. 3. If xmm16-xmm31/ymm16-ymm31 registers are used: a. With AVX512VL, AVX512VL vector moves will be generated. b. Without AVX512VL, xmm16-xmm31/ymm16-ymm31 register to register move will be done with zmm register move. There is no need to set mode attribute to XImode explicitly since ix86_output_ssemov can properly encode xmm16-xmm31/ymm16-ymm31 registers with and without AVX512VL. Tested on AVX2 and AVX512 with and without --with-arch=native. gcc/ PR target/89229 PR target/89346 * config/i386/i386-protos.h (ix86_output_ssemov): New prototype. * config/i386/i386.c (ix86_get_ssemov): New function. (ix86_output_ssemov): Likewise. * config/i386/sse.md (VMOVE:mov<mode>_internal): Call ix86_output_ssemov for TYPE_SSEMOV. Remove TARGET_AVX512VL check. (*movxi_internal_avx512f): Call ix86_output_ssemov for TYPE_SSEMOV. (*movoi_internal_avx): Call ix86_output_ssemov for TYPE_SSEMOV. Remove ext_sse_reg_operand and TARGET_AVX512VL check. (*movti_internal): Likewise. (*movtf_internal): Call ix86_output_ssemov for TYPE_SSEMOV. gcc/testsuite/ PR target/89229 PR target/89346 * gcc.target/i386/avx512vl-vmovdqa64-1.c: Updated. * gcc.target/i386/pr89229-2a.c: New test. * gcc.target/i386/pr89229-2b.c: Likewise. * gcc.target/i386/pr89229-2c.c: Likewise. * gcc.target/i386/pr89229-3a.c: Likewise. * gcc.target/i386/pr89229-3b.c: Likewise. * gcc.target/i386/pr89229-3c.c: Likewise. * gcc.target/i386/pr89346.c: Likewise.
