7f107c3019
While sinking instructions (that are loop invariant) from preheader to the exit block, we are skipping instructions due to decrementing instruction iterator twice.
53 lines
1.9 KiB
LLVM
53 lines
1.9 KiB
LLVM
; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 2
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; RUN: opt -S -passes='print<scalar-evolution>,indvars' < %s 2>/dev/null | FileCheck %s
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; We should use %invariant.op.us rather than %invariant.op for the exit
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; value expansion. They have the same SCEV, but %invariant.op is more
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; poisonous.
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define i32 @test(i1 %c) {
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; CHECK-LABEL: define i32 @test
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; CHECK-SAME: (i1 [[C:%.*]]) {
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; CHECK-NEXT: entry:
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; CHECK-NEXT: [[SEL:%.*]] = select i1 [[C]], i32 33, i32 0
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; CHECK-NEXT: [[SUB_I:%.*]] = add nsw i32 [[SEL]], -68
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; CHECK-NEXT: [[SHL_I:%.*]] = shl nuw nsw i32 1, [[SUB_I]]
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; CHECK-NEXT: [[ADD:%.*]] = add nsw i32 [[SHL_I]], [[SEL]]
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; CHECK-NEXT: [[SEXT:%.*]] = shl i32 [[ADD]], 24
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; CHECK-NEXT: [[CONV2:%.*]] = ashr exact i32 [[SEXT]], 24
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; CHECK-NEXT: [[INVARIANT_OP:%.*]] = sub nsw i32 7, [[CONV2]]
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; CHECK-NEXT: call void @use(i32 [[INVARIANT_OP]])
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; CHECK-NEXT: br label [[LOOP:%.*]]
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; CHECK: loop:
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; CHECK-NEXT: br i1 true, label [[EXIT:%.*]], label [[LOOP]]
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; CHECK: exit:
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; CHECK-NEXT: [[SEXT_US:%.*]] = shl i32 [[SEL]], 24
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; CHECK-NEXT: [[CONV2_US:%.*]] = ashr exact i32 [[SEXT_US]], 24
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; CHECK-NEXT: [[INVARIANT_OP_US:%.*]] = sub nsw i32 7, [[CONV2_US]]
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; CHECK-NEXT: ret i32 [[INVARIANT_OP_US]]
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;
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entry:
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%sel = select i1 %c, i32 33, i32 0
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%sub.i = add nsw i32 %sel, -68
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%shl.i = shl nuw nsw i32 1, %sub.i
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%add = add nsw i32 %shl.i, %sel
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%sext = shl i32 %add, 24
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%conv2 = ashr exact i32 %sext, 24
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%invariant.op = sub nsw i32 7, %conv2
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call void @use(i32 %invariant.op)
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%sext.us = shl i32 %sel, 24
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%conv2.us = ashr exact i32 %sext.us, 24
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%invariant.op.us = sub nsw i32 7, %conv2.us
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br label %loop
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loop:
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%iv = phi i32 [ %iv.next , %loop ], [ 0, %entry ]
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%iv.next = add i32 %iv, 1
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%cmp = icmp eq i32 %iv.next, %invariant.op.us
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br i1 %cmp, label %exit, label %loop
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exit:
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ret i32 %iv.next
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}
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declare void @use(i32)
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