[llvm] r347735 - [SystemZ::TTI] Improve cost for compare of i64 with extended i32 load
Jonas Paulsson via llvm-commits
llvm-commits at lists.llvm.org
Wed Nov 28 00:58:27 PST 2018
Author: jonpa
Date: Wed Nov 28 00:58:27 2018
New Revision: 347735
URL: http://llvm.org/viewvc/llvm-project?rev=347735&view=rev
Log:
[SystemZ::TTI] Improve cost for compare of i64 with extended i32 load
CGF/CLGF compares an i64 register with a sign/zero extended loaded i32 value
in memory.
This patch makes such a load considered foldable and so gets a 0 cost.
Review: Ulrich Weigand
https://reviews.llvm.org/D54944
Modified:
llvm/trunk/lib/Target/SystemZ/SystemZTargetTransformInfo.cpp
llvm/trunk/test/Analysis/CostModel/SystemZ/memop-folding-int-arith.ll
Modified: llvm/trunk/lib/Target/SystemZ/SystemZTargetTransformInfo.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/SystemZ/SystemZTargetTransformInfo.cpp?rev=347735&r1=347734&r2=347735&view=diff
==============================================================================
--- llvm/trunk/lib/Target/SystemZ/SystemZTargetTransformInfo.cpp (original)
+++ llvm/trunk/lib/Target/SystemZ/SystemZTargetTransformInfo.cpp Wed Nov 28 00:58:27 2018
@@ -915,16 +915,19 @@ isFoldableLoad(const LoadInst *Ld, const
switch (UserI->getOpcode()) {
case Instruction::Add: // SE: 16->32, 16/32->64, z14:16->64. ZE: 32->64
case Instruction::Sub:
+ case Instruction::ICmp:
if (LoadedBits == 32 && ZExtBits == 64)
return true;
LLVM_FALLTHROUGH;
case Instruction::Mul: // SE: 16->32, 32->64, z14:16->64
- if (LoadedBits == 16 &&
- (SExtBits == 32 ||
- (SExtBits == 64 && ST->hasMiscellaneousExtensions2())))
- return true;
- if (LoadOrTruncBits == 16)
- return true;
+ if (UserI->getOpcode() != Instruction::ICmp) {
+ if (LoadedBits == 16 &&
+ (SExtBits == 32 ||
+ (SExtBits == 64 && ST->hasMiscellaneousExtensions2())))
+ return true;
+ if (LoadOrTruncBits == 16)
+ return true;
+ }
LLVM_FALLTHROUGH;
case Instruction::SDiv:// SE: 32->64
if (LoadedBits == 32 && SExtBits == 64)
@@ -934,7 +937,6 @@ isFoldableLoad(const LoadInst *Ld, const
case Instruction::And:
case Instruction::Or:
case Instruction::Xor:
- case Instruction::ICmp:
// This also makes sense for float operations, but disabled for now due
// to regressions.
// case Instruction::FCmp:
Modified: llvm/trunk/test/Analysis/CostModel/SystemZ/memop-folding-int-arith.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Analysis/CostModel/SystemZ/memop-folding-int-arith.ll?rev=347735&r1=347734&r2=347735&view=diff
==============================================================================
--- llvm/trunk/test/Analysis/CostModel/SystemZ/memop-folding-int-arith.ll (original)
+++ llvm/trunk/test/Analysis/CostModel/SystemZ/memop-folding-int-arith.ll Wed Nov 28 00:58:27 2018
@@ -726,6 +726,16 @@ define void @icmp() {
%tr_0 = trunc i64 %li64_2 to i32
icmp eq i32 %tr_0, undef
+ ; Sign-extended load
+ %li32_2 = load i32, i32* undef
+ %sext = sext i32 %li32_2 to i64
+ icmp eq i64 %sext, undef
+
+ ; Zero-extended load
+ %li32_3 = load i32, i32* undef
+ %zext = zext i32 %li32_3 to i64
+ icmp eq i64 %zext, undef
+
; Loads with multiple uses are *not* folded
%li64_3 = load i64, i64* undef
%tr_1 = trunc i64 %li64_3 to i32
@@ -745,7 +755,13 @@ define void @icmp() {
; CHECK: Cost Model: Found an estimated cost of 0 for instruction: %li64_2 = load i64, i64* undef
; CHECK: Cost Model: Found an estimated cost of 0 for instruction: %tr_0 = trunc i64 %li64_2 to i32
; CHECK: Cost Model: Found an estimated cost of 1 for instruction: %5 = icmp eq i32 %tr_0, undef
+; CHECK: Cost Model: Found an estimated cost of 0 for instruction: %li32_2 = load i32, i32* undef
+; CHECK: Cost Model: Found an estimated cost of 0 for instruction: %sext = sext i32 %li32_2 to i64
+; CHECK: Cost Model: Found an estimated cost of 1 for instruction: %6 = icmp eq i64 %sext, undef
+; CHECK: Cost Model: Found an estimated cost of 0 for instruction: %li32_3 = load i32, i32* undef
+; CHECK: Cost Model: Found an estimated cost of 0 for instruction: %zext = zext i32 %li32_3 to i64
+; CHECK: Cost Model: Found an estimated cost of 1 for instruction: %7 = icmp eq i64 %zext, undef
; CHECK: Cost Model: Found an estimated cost of 1 for instruction: %li64_3 = load i64, i64* undef
; CHECK: Cost Model: Found an estimated cost of 0 for instruction: %tr_1 = trunc i64 %li64_3 to i32
-; CHECK: Cost Model: Found an estimated cost of 1 for instruction: %6 = icmp eq i64 %li64_3, undef
+; CHECK: Cost Model: Found an estimated cost of 1 for instruction: %8 = icmp eq i64 %li64_3, undef
}
More information about the llvm-commits
mailing list