49 lines
1.5 KiB
LLVM
49 lines
1.5 KiB
LLVM
; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
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; RUN: opt < %s -instcombine -S | FileCheck %s
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; Fold
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; x s/ (-1 << y)
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; to
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; -(x >> y)
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; iff x is known non-negative.
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declare void @llvm.assume(i1)
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define i8 @t0(i8 %x, i8 %y) {
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; CHECK-LABEL: @t0(
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; CHECK-NEXT: [[X_IS_NONNEGATIVE:%.*]] = icmp sgt i8 [[X:%.*]], -1
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; CHECK-NEXT: call void @llvm.assume(i1 [[X_IS_NONNEGATIVE]])
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; CHECK-NEXT: [[TMP1:%.*]] = lshr i8 [[X]], 5
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; CHECK-NEXT: [[DIV:%.*]] = sub nsw i8 0, [[TMP1]]
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; CHECK-NEXT: ret i8 [[DIV]]
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;
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%x_is_nonnegative = icmp sge i8 %x, 0
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call void @llvm.assume(i1 %x_is_nonnegative)
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%div = sdiv i8 %x, -32
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ret i8 %div
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}
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define i8 @n1(i8 %x, i8 %y) {
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; CHECK-LABEL: @n1(
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; CHECK-NEXT: [[X_IS_NONNEGATIVE:%.*]] = icmp sgt i8 [[X:%.*]], -2
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; CHECK-NEXT: call void @llvm.assume(i1 [[X_IS_NONNEGATIVE]])
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; CHECK-NEXT: [[DIV:%.*]] = sdiv i8 [[X]], -32
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; CHECK-NEXT: ret i8 [[DIV]]
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;
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%x_is_nonnegative = icmp sge i8 %x, -1 ; could be negative
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call void @llvm.assume(i1 %x_is_nonnegative)
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%div = sdiv i8 %x, -32
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ret i8 %div
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}
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define i8 @n2(i8 %x, i8 %y) {
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; CHECK-LABEL: @n2(
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; CHECK-NEXT: [[X_IS_NONNEGATIVE:%.*]] = icmp sgt i8 [[X:%.*]], -1
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; CHECK-NEXT: call void @llvm.assume(i1 [[X_IS_NONNEGATIVE]])
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; CHECK-NEXT: [[DIV:%.*]] = sdiv i8 [[X]], -31
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; CHECK-NEXT: ret i8 [[DIV]]
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;
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%x_is_nonnegative = icmp sge i8 %x, 0
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call void @llvm.assume(i1 %x_is_nonnegative)
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%div = sdiv i8 %x, -31 ; not a negative power of two
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ret i8 %div
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}
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