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[RISCV] Fix RISCVTTIImpl::getIntImmCost for immediates where getMinSignedBits() > 64 

APInt::getSExtValue will assert if getMinSignedBits() > 64. This can happen,
for instance, if examining an i128. Avoid this assertion by checking
Imm.getMinSignedBits() <= 64 before doing
getTLI()->isLegalAddImmediate(Imm.getSExtValue()). We could directly check
getMinSignedBits() <= 12 but it seems better to reuse the isLegalAddImmediate
helper for this.

Differential Revision: https://reviews.llvm.org/D64390

llvm-svn: 365462
This commit is contained in:
Alex Bradbury 2019-07-09 10:56:18 +00:00
parent 65d7511f38
commit e0831dac0c
2 changed files with 13 additions and 2 deletions
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4
llvm/lib/Target/RISCV/RISCVTargetTransformInfo.cpp
View File

@ -71,8 +71,10 @@ int RISCVTTIImpl::getIntImmCost(unsigned Opcode, unsigned Idx, const APInt &Imm,
// Check immediate is the correct argument...
if (Instruction::isCommutative(Opcode) || Idx == ImmArgIdx) {
// ... and fits into the 12-bit immediate.
if (getTLI()->isLegalAddImmediate(Imm.getSExtValue()))
if (Imm.getMinSignedBits() <= 64 &&
getTLI()->isLegalAddImmediate(Imm.getSExtValue())) {
return TTI::TCC_Free;
}
}
// Otherwise, use the full materialisation cost.

11
llvm/test/Transforms/ConstantHoisting/RISCV/immediates.ll
View File

@ -26,4 +26,13 @@ define i64 @test3(i64 %a) nounwind {
%1 = mul i64 %a, 32767
%2 = add i64 %1, 32767
ret i64 %2
}
}
; Check that we hoist immediates with very large values.
define i128 @test4(i128 %a) nounwind {
; CHECK-LABEL: test4
; CHECK: %const = bitcast i128 12297829382473034410122878 to i128
%1 = add i128 %a, 12297829382473034410122878
%2 = add i128 %1, 12297829382473034410122878
ret i128 %2
}