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.
