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| author | Hans Wennborg <hans@chromium.org> | 2019-11-13 11:59:22 +0100 |
|---|---|---|
| committer | Hans Wennborg <hans@chromium.org> | 2019-11-13 12:19:02 +0100 |
| commit | 6ea47759008526dc11f5064b266de95c61915581 (patch) | |
| tree | c722d72d7942805728803ac106eeb7ba3c362b89 /llvm/test/Transforms/FunctionAttrs | |
| parent | fed17867cd42c5fa8a7a561637d539fbde6f511f (diff) | |
| download | bcm5719-llvm-6ea47759008526dc11f5064b266de95c61915581.tar.gz bcm5719-llvm-6ea47759008526dc11f5064b266de95c61915581.zip | |
Revert 57dd4b0 "[ValueTracking] Allow context-sensitive nullness check for non-pointers"
This caused miscompiles of Chromium (https://crbug.com/1023818). The reduced
repro is small enough to fit here:
$ cat /tmp/a.c
unsigned char f(unsigned char *p) {
unsigned char result = 0;
for (int shift = 0; shift < 1; ++shift)
result |= p[0] << (shift * 8);
return result;
}
$ bin/clang -O2 -S -o - /tmp/a.c | grep -A4 f:
f: # @f
.cfi_startproc
# %bb.0: # %entry
xorl %eax, %eax
retq
That's nicely optimized, but I don't think it's the right result :-)
> Same as D60846 but with a fix for the problem encountered there which
> was a missing context adjustment in the handling of PHI nodes.
>
> The test that caused D60846 to be reverted was added in e15ab8f277c7.
>
> Reviewers: nikic, nlopes, mkazantsev,spatel, dlrobertson, uabelho, hakzsam
>
> Subscribers: hiraditya, bollu, llvm-commits
>
> Tags: #llvm
>
> Differential Revision: https://reviews.llvm.org/D69571
This reverts commit 57dd4b03e4806bbb4760ab6150940150d884df20.
Diffstat (limited to 'llvm/test/Transforms/FunctionAttrs')
| -rw-r--r-- | llvm/test/Transforms/FunctionAttrs/nonnull.ll | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/llvm/test/Transforms/FunctionAttrs/nonnull.ll b/llvm/test/Transforms/FunctionAttrs/nonnull.ll index acdda1df0ae..42923cee770 100644 --- a/llvm/test/Transforms/FunctionAttrs/nonnull.ll +++ b/llvm/test/Transforms/FunctionAttrs/nonnull.ll @@ -873,7 +873,7 @@ define void @PR43833_simple(i32* %0, i32 %1) { ; ATTRIBUTOR_NPM-NEXT: ret void ; ATTRIBUTOR_NPM: 8: ; ATTRIBUTOR_NPM-NEXT: [[TMP9:%.*]] = phi i32 [ 1, [[TMP4]] ], [ [[TMP10:%.*]], [[TMP8]] ] -; ATTRIBUTOR_NPM-NEXT: tail call void @sink(i32* nonnull [[TMP6]]) +; ATTRIBUTOR_NPM-NEXT: tail call void @sink(i32* [[TMP6]]) ; ATTRIBUTOR_NPM-NEXT: [[TMP10]] = add nuw nsw i32 [[TMP9]], 1 ; ATTRIBUTOR_NPM-NEXT: [[TMP11:%.*]] = icmp eq i32 [[TMP10]], [[TMP1]] ; ATTRIBUTOR_NPM-NEXT: br i1 [[TMP11]], label [[TMP7]], label [[TMP8]] |
