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; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
; RUN: opt < %s -passes=instcombine -S | FileCheck %s
; Fold
; x s/ (-1 << y)
; to
; -(x >> y)
; iff x is known non-negative.
declare void @llvm.assume(i1)
define i8 @t0(i8 %x, i8 %y) {
; CHECK-LABEL: @t0(
; CHECK-NEXT: [[X_IS_NONNEGATIVE:%.*]] = icmp sgt i8 [[X:%.*]], -1
; CHECK-NEXT: call void @llvm.assume(i1 [[X_IS_NONNEGATIVE]])
; CHECK-NEXT: [[DIV1:%.*]] = lshr i8 [[X]], 5
; CHECK-NEXT: [[DIV:%.*]] = sub nsw i8 0, [[DIV1]]
; CHECK-NEXT: ret i8 [[DIV]]
;
%x_is_nonnegative = icmp sge i8 %x, 0
call void @llvm.assume(i1 %x_is_nonnegative)
%div = sdiv i8 %x, -32
ret i8 %div
}
define i8 @n1(i8 %x, i8 %y) {
; CHECK-LABEL: @n1(
; CHECK-NEXT: [[X_IS_NONNEGATIVE:%.*]] = icmp sgt i8 [[X:%.*]], -2
; CHECK-NEXT: call void @llvm.assume(i1 [[X_IS_NONNEGATIVE]])
; CHECK-NEXT: [[DIV:%.*]] = sdiv i8 [[X]], -32
; CHECK-NEXT: ret i8 [[DIV]]
;
%x_is_nonnegative = icmp sge i8 %x, -1 ; could be negative
call void @llvm.assume(i1 %x_is_nonnegative)
%div = sdiv i8 %x, -32
ret i8 %div
}
define i8 @n2(i8 %x, i8 %y) {
; CHECK-LABEL: @n2(
; CHECK-NEXT: [[X_IS_NONNEGATIVE:%.*]] = icmp sgt i8 [[X:%.*]], -1
; CHECK-NEXT: call void @llvm.assume(i1 [[X_IS_NONNEGATIVE]])
; CHECK-NEXT: [[DIV:%.*]] = sdiv i8 [[X]], -31
; CHECK-NEXT: ret i8 [[DIV]]
;
%x_is_nonnegative = icmp sge i8 %x, 0
call void @llvm.assume(i1 %x_is_nonnegative)
%div = sdiv i8 %x, -31 ; not a negative power of two
ret i8 %div
}
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