[llvm] a0869b1 - [CostModel][X86] Fix expanded CTPOP i8 costs

[Simon Pilgrim via llvm-commits]

Author: Simon Pilgrim
Date: 2024-02-21T14:54:50Z
New Revision: a0869b14cde9ed71bb4323c8717f59ee1b1e79bf

URL: https://github.com/llvm/llvm-project/commit/a0869b14cde9ed71bb4323c8717f59ee1b1e79bf
DIFF: https://github.com/llvm/llvm-project/commit/a0869b14cde9ed71bb4323c8717f59ee1b1e79bf.diff

LOG: [CostModel][X86] Fix expanded CTPOP i8 costs

Updated to match #79989 / 9410019ac977141bc73aee19690b5896ded59219

Added: 
    

Modified: 
    llvm/lib/Target/X86/X86TargetTransformInfo.cpp
    llvm/test/Analysis/CostModel/X86/ctpop-codesize.ll
    llvm/test/Analysis/CostModel/X86/ctpop-sizelatency.ll

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Target/X86/X86TargetTransformInfo.cpp b/llvm/lib/Target/X86/X86TargetTransformInfo.cpp
index be1a0948308999..f91e13f997f788 100644
--- a/llvm/lib/Target/X86/X86TargetTransformInfo.cpp
+++ b/llvm/lib/Target/X86/X86TargetTransformInfo.cpp
@@ -4000,7 +4000,7 @@ X86TTIImpl::getIntrinsicInstrCost(const IntrinsicCostAttributes &ICA,
     { ISD::CTTZ_ZERO_UNDEF, MVT::i8, {  2,  2,  1,  1 } }, // BSF
     { ISD::CTPOP,      MVT::i32,     {  8,  7, 15, 15 } },
     { ISD::CTPOP,      MVT::i16,     {  9,  8, 17, 17 } },
-    { ISD::CTPOP,      MVT::i8,      {  7,  6, 13, 13 } },
+    { ISD::CTPOP,      MVT::i8,      {  7,  6,  6,  6 } },
     { ISD::ROTL,       MVT::i32,     {  2,  3,  1,  3 } },
     { ISD::ROTL,       MVT::i16,     {  2,  3,  1,  3 } },
     { ISD::ROTL,       MVT::i8,      {  2,  3,  1,  3 } },

diff  --git a/llvm/test/Analysis/CostModel/X86/ctpop-codesize.ll b/llvm/test/Analysis/CostModel/X86/ctpop-codesize.ll
index 75adeee09197e8..2e417efd52d123 100644
--- a/llvm/test/Analysis/CostModel/X86/ctpop-codesize.ll
+++ b/llvm/test/Analysis/CostModel/X86/ctpop-codesize.ll
@@ -57,7 +57,7 @@ define i16 @var_ctpop_i16(i16 %a) {
 
 define i8 @var_ctpop_i8(i8 %a) {
 ; NOPOPCNT-LABEL: 'var_ctpop_i8'
-; NOPOPCNT-NEXT:  Cost Model: Found an estimated cost of 13 for instruction: %ctpop = call i8 @llvm.ctpop.i8(i8 %a)
+; NOPOPCNT-NEXT:  Cost Model: Found an estimated cost of 6 for instruction: %ctpop = call i8 @llvm.ctpop.i8(i8 %a)
 ; NOPOPCNT-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: ret i8 %ctpop
 ;
 ; POPCNT-LABEL: 'var_ctpop_i8'

diff  --git a/llvm/test/Analysis/CostModel/X86/ctpop-sizelatency.ll b/llvm/test/Analysis/CostModel/X86/ctpop-sizelatency.ll
index b46cfe15569e66..0e629c23b71cad 100644
--- a/llvm/test/Analysis/CostModel/X86/ctpop-sizelatency.ll
+++ b/llvm/test/Analysis/CostModel/X86/ctpop-sizelatency.ll
@@ -57,7 +57,7 @@ define i16 @var_ctpop_i16(i16 %a) {
 
 define i8 @var_ctpop_i8(i8 %a) {
 ; NOPOPCNT-LABEL: 'var_ctpop_i8'
-; NOPOPCNT-NEXT:  Cost Model: Found an estimated cost of 13 for instruction: %ctpop = call i8 @llvm.ctpop.i8(i8 %a)
+; NOPOPCNT-NEXT:  Cost Model: Found an estimated cost of 6 for instruction: %ctpop = call i8 @llvm.ctpop.i8(i8 %a)
 ; NOPOPCNT-NEXT:  Cost Model: Found an estimated cost of 1 for instruction: ret i8 %ctpop
 ;
 ; POPCNT-LABEL: 'var_ctpop_i8'