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[RISCV] Correct RISCVTTIImpl::getIntImmCostInst for Zba #128174

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Merged
merged 1 commit into from
Feb 27, 2025
Merged

[RISCV] Correct RISCVTTIImpl::getIntImmCostInst for Zba #128174

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3 changes: 2 additions & 1 deletion llvm/lib/Target/RISCV/RISCVTargetTransformInfo.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -207,7 +207,8 @@ InstructionCost RISCVTTIImpl::getIntImmCostInst(unsigned Opcode, unsigned Idx,
if (Imm == UINT64_C(0xffff) && ST->hasStdExtZbb())
return TTI::TCC_Free;
// zext.w
if (Imm == UINT64_C(0xffffffff) && ST->hasStdExtZba())
if (Imm == UINT64_C(0xffffffff) &&
((ST->hasStdExtZba() && ST->isRV64()) || ST->isRV32()))
return TTI::TCC_Free;
// bclri
if (ST->hasStdExtZbs() && (~Imm).isPowerOf2())
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17 changes: 11 additions & 6 deletions llvm/test/Transforms/ConstantHoisting/RISCV/immediates.ll
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@@ -1,5 +1,5 @@
; RUN: opt -mtriple=riscv32-unknown-elf -S -passes=consthoist < %s | FileCheck %s
; RUN: opt -mtriple=riscv64-unknown-elf -S -passes=consthoist < %s | FileCheck %s
; RUN: opt -mtriple=riscv32-unknown-elf -S -passes=consthoist < %s | FileCheck %s -check-prefixes=CHECK,RV32I
; RUN: opt -mtriple=riscv64-unknown-elf -S -passes=consthoist < %s | FileCheck %s -check-prefixes=CHECK,RV64I

; Check that we don't hoist immediates with small values.
define i64 @test1(i64 %a) nounwind {
Expand Down Expand Up @@ -55,16 +55,21 @@ define i32 @test6(i32 %a) nounwind "target-features"="+zbb" {
ret i32 %2
}

; Check that we hoist zext.w without Zba.
; Check that we hoist zext.w without Zba on RV64.
; Check that we don't hoist on RV32.
define i64 @test7(i64 %a) nounwind {
; CHECK-LABEL: test7
; CHECK: %const = bitcast i64 4294967295 to i64
; RV32I-LABEL: test7
; RV32I: and i64 %a, 4294967295

; RV64I-LABEL: test7
; RV64I: %const = bitcast i64 4294967295 to i64
%1 = and i64 %a, 4294967295
%2 = and i64 %1, 4294967295
ret i64 %2
}

; Check that we don't hoist zext.w with Zba.
; Check that we don't hoist zext.w with Zba on RV64.
; Check that we don't hoist on RV32.
define i64 @test8(i64 %a) nounwind "target-features"="+zba" {
; CHECK-LABEL: test8
; CHECK: and i64 %a, 4294967295
Expand Down