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[NFC][InstCombine] Add some tests with sdiv-by-negative-power-of-two
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llvm/test/Transforms/InstCombine/sdiv-of-non-negative-by-negative-power-of-two.ll
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; NOTE: Assertions have been autogenerated by utils/update_test_checks.py | ||
; RUN: opt %s -instcombine -S | FileCheck %s | ||
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; Fold | ||
; x s/ (-1 << y) | ||
; to | ||
; -(x >> y) | ||
; 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) { | ||
; 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: [[DIV:%.*]] = sdiv i8 [[X]], -32 | ||
; 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 | ||
} |