As discussed in issue #37809, this transform is not safe
if the input is an undefined value.
There is no difference in codegen on the basic examples,
but this could lead to regressions. We may need to
improve freeze analysis or lowering if that happens.
Div/rem by zero is immediate undefined behavior and anything goes.
Currently we fold it to undef, this patch changes it to fold to
poison instead, which is slightly stronger.
Differential Revision: https://reviews.llvm.org/D93995
As described here:
https://bugs.llvm.org/show_bug.cgi?id=44186
The match() code safely allows undef values, but we can't safely
propagate a vector constant that contains an undef to the new
compare instruction.
As it's causing some bot failures (and per request from kbarton).
This reverts commit r358543/ab70da07286e618016e78247e4a24fcb84077fda.
llvm-svn: 358546
Generalize existing constant matching to work with non-uniform constant vectors as well.
Differential Revision: https://reviews.llvm.org/D42818
llvm-svn: 324369
