65 lines
2.2 KiB
LLVM
65 lines
2.2 KiB
LLVM
; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
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; RUN: opt < %s -reassociate -S | FileCheck %s
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define i32 @shl_add(i8 %x) {
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; CHECK-LABEL: @shl_add(
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; CHECK-NEXT: [[CONV:%.*]] = zext i8 [[X:%.*]] to i32
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; CHECK-NEXT: [[SHL:%.*]] = shl nuw nsw i32 [[CONV]], 8
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; CHECK-NEXT: [[SHL2:%.*]] = shl nuw nsw i32 [[CONV]], 16
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; CHECK-NEXT: [[ADD:%.*]] = add nuw nsw i32 [[SHL]], [[SHL2]]
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; CHECK-NEXT: ret i32 [[ADD]]
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;
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%conv = zext i8 %x to i32
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%shl = shl nuw nsw i32 %conv, 8
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%shl2 = shl nuw nsw i32 %conv, 16
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%add = or i32 %shl, %shl2
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ret i32 %add
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}
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; If we don't know that operands have no common bits set,
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; we can't convert the `or` into an `add`.
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define i32 @test1(i32 %a, i32 %b) {
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; CHECK-LABEL: @test1(
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; CHECK-NEXT: [[C:%.*]] = or i32 [[B:%.*]], [[A:%.*]]
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; CHECK-NEXT: [[C_PLUS_ONE:%.*]] = add i32 [[C]], 1
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; CHECK-NEXT: ret i32 [[C_PLUS_ONE]]
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;
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%c = or i32 %a, %b
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%c.plus.one = add i32 %c, 1
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ret i32 %c.plus.one
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}
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; But if we *do* know that operands have no common bits set,
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; we *can* convert the `or` into an `add`.
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define i32 @test2(i32 %x, i32 %y) {
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; CHECK-LABEL: @test2(
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; CHECK-NEXT: [[X_NUMLZ:%.*]] = tail call i32 @llvm.ctlz.i32(i32 [[X:%.*]], i1 true), [[RNG0:!range !.*]]
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; CHECK-NEXT: [[RES:%.*]] = add nuw nsw i32 [[X_NUMLZ]], -32
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; CHECK-NEXT: [[RES_PLUS_ONE:%.*]] = add i32 [[RES]], [[Y:%.*]]
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; CHECK-NEXT: ret i32 [[RES_PLUS_ONE]]
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;
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%x.numlz = tail call i32 @llvm.ctlz.i32(i32 %x, i1 true), !range !0
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%res = or i32 %x.numlz, -32
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%res.plus.one = add i32 %res, %y
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ret i32 %res.plus.one
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}
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; And that allows reassociation in general.
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define i32 @test3(i32 %x, i32 %bit) {
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; CHECK-LABEL: @test3(
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; CHECK-NEXT: [[X_NUMLZ:%.*]] = tail call i32 @llvm.ctlz.i32(i32 [[X:%.*]], i1 true), [[RNG0]]
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; CHECK-NEXT: [[BIT_PLUS_ONE:%.*]] = add i32 [[BIT:%.*]], -31
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; CHECK-NEXT: [[RES:%.*]] = add i32 [[BIT_PLUS_ONE]], [[X_NUMLZ]]
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; CHECK-NEXT: ret i32 [[RES]]
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;
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%x.numlz = tail call i32 @llvm.ctlz.i32(i32 %x, i1 true), !range !0
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%zero.minus.x.numactivebits = or i32 %x.numlz, -32
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%bit.plus.one = add i32 %bit, 1
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%res = add i32 %bit.plus.one, %zero.minus.x.numactivebits
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ret i32 %res
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}
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declare i32 @llvm.ctlz.i32(i32, i1 immarg) #2
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!0 = !{i32 0, i32 33}
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