mirror of
https://github.com/c64scene-ar/llvm-6502.git
synced 2024-07-24 23:29:41 +00:00
2ceba77dfa
When creating a scev for sext({X,+,Y}), scev checks if the expression
is equivalent to {sext X,+,zext Y}. If it can prove that, it also
tags the original {X,+,Y} as <nsw>, which is not correct.
In the test case I run `-scalar-evolution` twice because the bug
manifests only once SCEV has run through and seen the `sext`
expressions (and then does a in-place mutation on {X,+,Y}).
Differential Revision: http://reviews.llvm.org/D7495
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@228586 91177308-0d34-0410-b5e6-96231b3b80d8
27 lines
689 B
LLVM
27 lines
689 B
LLVM
; RUN: opt -analyze -scalar-evolution -scalar-evolution < %s | FileCheck %s
|
|
|
|
define void @bad.nsw() {
|
|
; CHECK-LABEL: Classifying expressions for: @bad.nsw
|
|
; CHECK-LABEL: Classifying expressions for: @bad.nsw
|
|
entry:
|
|
br label %loop
|
|
|
|
loop:
|
|
%i = phi i8 [ -1, %entry ], [ %i.inc, %loop ]
|
|
; CHECK: %i = phi i8 [ -1, %entry ], [ %i.inc, %loop ]
|
|
; CHECK-NEXT: --> {-1,+,-128}<nw><%loop>
|
|
; CHECK-NOT: --> {-1,+,-128}<nsw><%loop>
|
|
|
|
%counter = phi i8 [ 0, %entry ], [ %counter.inc, %loop ]
|
|
|
|
%i.inc = add i8 %i, -128
|
|
%i.sext = sext i8 %i to i16
|
|
|
|
%counter.inc = add i8 %counter, 1
|
|
%continue = icmp eq i8 %counter, 1
|
|
br i1 %continue, label %exit, label %loop
|
|
|
|
exit:
|
|
ret void
|
|
}
|