[X86] Add SchedRW for PMULLD
Summary:
It seems many CPUs don't implement this instruction as well as the other vector multiplies. Often using a multi uop flow. Silvermont in particular has a 7 uop flow with 11 cycle throughput. Sandy Bridge implements it as a single uop with 5 cycle latency and 1 cycle throughput. But Haswell and later use 2 uops with 10 cycle latency and 2 cycle throughput.
This patch adds a new X86SchedWritePair we can use to tag this instruction separately. I've provided correct information for Silvermont, Btver2, and Sandy Bridge. I've removed the InstRWs for SandyBridge. I've left Haswell/Broadwell/Skylake InstRWs in place because I wasn't sure how to account for the different load latency between 128 and 256 bits. I also left Znver1 InstRWs in place because the existing values don't match Agner's spreadsheet.
I also left a FIXME in the SandyBridge model because it being used for the "generic" model is too optimistic for the 256/512-bit versions since those are multiple uops on all known CPUs.
Reviewers: RKSimon, GGanesh, courbet
Reviewed By: RKSimon
Subscribers: gchatelet, gbedwell, andreadb, llvm-commits
Differential Revision: https://reviews.llvm.org/D44972
llvm-svn: 328914
diff --git a/llvm/lib/Target/X86/X86InstrAVX512.td b/llvm/lib/Target/X86/X86InstrAVX512.td
index 663f2d1..188a167 100644
--- a/llvm/lib/Target/X86/X86InstrAVX512.td
+++ b/llvm/lib/Target/X86/X86InstrAVX512.td
@@ -4505,7 +4505,7 @@
defm VPSUBUS : avx512_binop_rm_vl_bw<0xD8, 0xD9, "vpsubus", X86subus,
SSE_INTALU_ITINS_P, HasBWI, 0>;
defm VPMULLD : avx512_binop_rm_vl_d<0x40, "vpmulld", mul,
- SSE_INTMUL_ITINS_P, HasAVX512, 1>, T8PD;
+ SSE_PMULLD_ITINS, HasAVX512, 1>, T8PD;
defm VPMULLW : avx512_binop_rm_vl_w<0xD5, "vpmullw", mul,
SSE_INTMUL_ITINS_P, HasBWI, 1>;
defm VPMULLQ : avx512_binop_rm_vl_q<0x40, "vpmullq", mul,