An intermediate extend is used to widen the narrow operand to the width of
the other (wider) operand. At that point, we have the same logic as the
existing transform that was restricted to folds of equal width zext/sext.
This mostly solves PR42700:
https://bugs.llvm.org/show_bug.cgi?id=42700
llvm-svn: 369519
As it's causing some bot failures (and per request from kbarton).
This reverts commit r358543/ab70da07286e618016e78247e4a24fcb84077fda.
llvm-svn: 358546
In r271810 ( http://reviews.llvm.org/rL271810 ), I loosened the check
above this to work for any Constant rather than ConstantInt. AFAICT,
that part makes sense if we can determine that the shrunken/extended
constant remained equal. But it doesn't make sense for this later
transform where we assume that the constant DID change.
This could assert for a ConstantExpr:
https://llvm.org/bugs/show_bug.cgi?id=28011
And it could be wrong for a vector as shown in the added regression test.
llvm-svn: 271908
Sanjay Patel