diff options
Diffstat (limited to 'llvm/test/Transforms/LoopStrengthReduce/lsr-expand-quadratic.ll')
| -rw-r--r-- | llvm/test/Transforms/LoopStrengthReduce/lsr-expand-quadratic.ll | 42 |
1 files changed, 42 insertions, 0 deletions
diff --git a/llvm/test/Transforms/LoopStrengthReduce/lsr-expand-quadratic.ll b/llvm/test/Transforms/LoopStrengthReduce/lsr-expand-quadratic.ll new file mode 100644 index 00000000000..255cf41a817 --- /dev/null +++ b/llvm/test/Transforms/LoopStrengthReduce/lsr-expand-quadratic.ll @@ -0,0 +1,42 @@ +; RUN: opt -loop-reduce -S < %s | FileCheck %s + +target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64-S128" +target triple = "x86_64-apple-macosx" + +; PR15470: LSR miscompile. The test2 function should return '1'. +; +; SCEV expander cannot expand quadratic recurrences outside of the +; loop. This recurrence depends on %sub.us, so can't be expanded. +; +; CHECK-LABEL: @test2 +; CHECK-LABEL: test2.loop: +; CHECK: %lsr.iv = phi i32 [ %lsr.iv.next, %test2.loop ], [ -16777216, %entry ] +; CHECK: %lsr.iv.next = add nsw i32 %lsr.iv, 16777216 +; +; CHECK=LABEL: for.end: +; CHECK: %sub.cond.us = sub nsw i32 %inc1115.us, %sub.us +; CHECK: %sext.us = mul i32 %lsr.iv.next, %sub.cond.us +; CHECK: %f = ashr i32 %sext.us, 24 +; CHECK: ret i32 %f +define i32 @test2() { +entry: + br label %test2.loop + +test2.loop: + %inc1115.us = phi i32 [ 0, %entry ], [ %inc11.us, %test2.loop ] + %inc11.us = add nsw i32 %inc1115.us, 1 + %cmp.us = icmp slt i32 %inc11.us, 2 + br i1 %cmp.us, label %test2.loop, label %for.end + +for.end: + %tobool.us = icmp eq i32 %inc1115.us, 0 + %sub.us = select i1 %tobool.us, i32 0, i32 0 + %mul.us = shl i32 %inc1115.us, 24 + %sub.cond.us = sub nsw i32 %inc1115.us, %sub.us + %sext.us = mul i32 %mul.us, %sub.cond.us + %f = ashr i32 %sext.us, 24 + br label %exit + +exit: + ret i32 %f +} |
