9a5b0f302b
This reapplies #132522. Previously casts of scalable m_ImmConstant splats weren't being folded by ConstantFoldCastOperand, triggering the "Constant-fold of ImmConstant should not fail" assertion. There are no changes to the code in this PR, instead we just needed #133207 to land first. A test has been added for the assertion in llvm/test/Transforms/InstSimplify/vec-icmp-of-cast.ll @icmp_ult_sext_scalable_splat_is_true. <hr/> #118806 fixed an infinite loop in FoldShiftByConstant that could occur when the shift amount was a ConstantExpr. However this meant that FoldShiftByConstant no longer kicked in for scalable vectors because scalable splats are represented by ConstantExprs. This fixes it by allowing scalable splats of non-ConstantExprs in m_ImmConstant, which also fixes a few other test cases where scalable splats were being missed. But I'm also hoping that UseConstantIntForScalableSplat will eventually remove the need for this. I noticed this when trying to reverse a combine on RISC-V in #132245, and saw that the resulting vector and scalar forms were different.
28 lines
1.3 KiB
LLVM
28 lines
1.3 KiB
LLVM
; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
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; RUN: opt < %s -passes=instcombine -S | FileCheck %s
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@c = external constant i8
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@c2 = external constant i8
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define i64 @testfunc() {
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; CHECK-LABEL: @testfunc(
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; CHECK-NEXT: [[SHL1:%.*]] = shl nuw i64 1, ptrtoint (ptr @c2 to i64)
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; CHECK-NEXT: [[SHL2:%.*]] = shl i64 [[SHL1]], ptrtoint (ptr @c to i64)
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; CHECK-NEXT: ret i64 [[SHL2]]
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;
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%shl1 = shl i64 1, ptrtoint (ptr @c2 to i64)
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%shl2 = shl i64 %shl1, ptrtoint (ptr @c to i64)
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ret i64 %shl2
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}
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define <vscale x 1 x i64> @scalable() {
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; CHECK-LABEL: @scalable(
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; CHECK-NEXT: [[SHL1:%.*]] = shl nuw <vscale x 1 x i64> splat (i64 1), shufflevector (<vscale x 1 x i64> insertelement (<vscale x 1 x i64> poison, i64 ptrtoint (ptr @c2 to i64), i64 0), <vscale x 1 x i64> poison, <vscale x 1 x i32> zeroinitializer)
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; CHECK-NEXT: [[SHL2:%.*]] = shl <vscale x 1 x i64> [[SHL1]], shufflevector (<vscale x 1 x i64> insertelement (<vscale x 1 x i64> poison, i64 ptrtoint (ptr @c to i64), i64 0), <vscale x 1 x i64> poison, <vscale x 1 x i32> zeroinitializer)
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; CHECK-NEXT: ret <vscale x 1 x i64> [[SHL2]]
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;
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%shl1 = shl <vscale x 1 x i64> splat (i64 1), splat (i64 ptrtoint (ptr @c2 to i64))
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%shl2 = shl <vscale x 1 x i64> %shl1, splat (i64 ptrtoint (ptr @c to i64))
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ret <vscale x 1 x i64> %shl2
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}
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