c3b9c36f3a
This patch propagates exact flags for `ashr->lshr` and `sdiv->udiv` in SCCP. This missed optimization is discovered with the help of https://github.com/AliveToolkit/alive2/pull/962.
29 lines
868 B
LLVM
29 lines
868 B
LLVM
; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 4
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; RUN: opt -passes=sccp < %s -S | FileCheck %s
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define i8 @ashr_to_lshr(i8 %x, i8 %y) {
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; CHECK-LABEL: define i8 @ashr_to_lshr(
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; CHECK-SAME: i8 [[X:%.*]], i8 [[Y:%.*]]) {
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; CHECK-NEXT: [[P:%.*]] = and i8 [[X]], 127
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; CHECK-NEXT: [[R:%.*]] = lshr exact i8 [[P]], [[Y]]
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; CHECK-NEXT: ret i8 [[R]]
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;
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%p = and i8 %x, 127
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%r = ashr exact i8 %p, %y
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ret i8 %r
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}
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define i8 @sdiv_to_udiv(i8 %x, i8 %y) {
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; CHECK-LABEL: define i8 @sdiv_to_udiv(
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; CHECK-SAME: i8 [[X:%.*]], i8 [[Y:%.*]]) {
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; CHECK-NEXT: [[X1:%.*]] = and i8 [[X]], 127
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; CHECK-NEXT: [[Y1:%.*]] = and i8 [[Y]], 127
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; CHECK-NEXT: [[R:%.*]] = udiv exact i8 [[X1]], [[Y1]]
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; CHECK-NEXT: ret i8 [[R]]
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;
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%x1 = and i8 %x, 127
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%y1 = and i8 %y, 127
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%r = sdiv exact i8 %x1, %y1
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ret i8 %r
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}
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