mirror of
https://github.com/c64scene-ar/llvm-6502.git
synced 2024-12-21 00:32:23 +00:00
c0f2b8b528
LinearFunctionTestReplace tries to use the *next* indvar to compare against when possible. However, it may be the case that the calculation for the next indvar has NUW/NSW flags and that it may only be safely used inside the loop. Using it in a comparison to calculate the exit condition could result in observing poison. This fixes PR20680. Differential Revision: http://reviews.llvm.org/D5174 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217102 91177308-0d34-0410-b5e6-96231b3b80d8
45 lines
1.3 KiB
LLVM
45 lines
1.3 KiB
LLVM
;RUN: opt -S %s -indvars | FileCheck %s
|
|
|
|
; CHECK-LABEL: @foo(
|
|
; CHECK-NOT: %lftr.wideiv = trunc i32 %indvars.iv.next to i16
|
|
; CHECK: %exitcond = icmp ne i32 %indvars.iv, 511
|
|
define void @foo() #0 {
|
|
entry:
|
|
br label %for.body
|
|
|
|
for.body: ; preds = %entry, %for.body
|
|
%i.01 = phi i16 [ 0, %entry ], [ %inc, %for.body ]
|
|
%conv2 = sext i16 %i.01 to i32
|
|
call void @bar(i32 %conv2) #1
|
|
%inc = add i16 %i.01, 1
|
|
%cmp = icmp slt i16 %inc, 512
|
|
br i1 %cmp, label %for.body, label %for.end
|
|
|
|
for.end: ; preds = %for.body
|
|
ret void
|
|
}
|
|
|
|
; Check that post-incrementing the backedge taken count does not overflow.
|
|
; CHECK-LABEL: @postinc(
|
|
; CHECK: icmp eq i32 %indvars.iv, 255
|
|
define i32 @postinc() #0 {
|
|
entry:
|
|
br label %do.body
|
|
|
|
do.body: ; preds = %do.body, %entry
|
|
%first.0 = phi i8 [ 0, %entry ], [ %inc, %do.body ]
|
|
%conv = zext i8 %first.0 to i32
|
|
call void @bar(i32 %conv) #1
|
|
%inc = add i8 %first.0, 1
|
|
%cmp = icmp eq i8 %first.0, -1
|
|
br i1 %cmp, label %do.end, label %do.body
|
|
|
|
do.end: ; preds = %do.body
|
|
ret i32 0
|
|
}
|
|
|
|
declare void @bar(i32)
|
|
|
|
attributes #0 = { nounwind uwtable }
|
|
attributes #1 = { nounwind }
|