llvm/test/CodeGen/X86/negative-stride-fptosi-user.ll
Dan Gohman a8225083ba Make LSR's OptimizeShadowIV ignore induction variables with negative
strides for now, because it doesn't handle them correctly. This fixes a
miscompile of SingleSource/Benchmarks/Misc-C++/ray.

This problem was usually hidden because indvars transforms such induction
variables into negations of canonical induction variables.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@85118 91177308-0d34-0410-b5e6-96231b3b80d8
2009-10-26 15:32:57 +00:00

26 lines
1004 B
LLVM

; RUN: llc < %s -march=x86-64 | grep cvtsi2sd
; LSR previously eliminated the sitofp by introducing an induction
; variable which stepped by a bogus ((double)UINT32_C(-1)). It's theoretically
; possible to eliminate the sitofp using a proper -1.0 step though; this
; test should be changed if that is done.
define void @foo(i32 %N) nounwind {
entry:
%0 = icmp slt i32 %N, 0 ; <i1> [#uses=1]
br i1 %0, label %bb, label %return
bb: ; preds = %bb, %entry
%i.03 = phi i32 [ 0, %entry ], [ %2, %bb ] ; <i32> [#uses=2]
%1 = sitofp i32 %i.03 to double ; <double> [#uses=1]
tail call void @bar(double %1) nounwind
%2 = add nsw i32 %i.03, -1 ; <i32> [#uses=2]
%exitcond = icmp eq i32 %2, %N ; <i1> [#uses=1]
br i1 %exitcond, label %return, label %bb
return: ; preds = %bb, %entry
ret void
}
declare void @bar(double)