Commit Graph

10 Commits

Author SHA1 Message Date
Craig Topper 924f20262b [InstCombine][InstSimplify] Teach decomposeBitTestICmp to look through truncate instructions
This patch teaches decomposeBitTestICmp to look through truncate instructions on the input to the compare. If a truncate is found it will now return the pre-truncated Value and appropriately extend the APInt mask.

This allows some code to be removed from InstSimplify that was doing this functionality.

This allows InstCombine's bit test combining code to match a pre-truncate Value with the same Value appear with an 'and' on another icmp. Or it allows us to combine a truncate to i16 and a truncate to i8. This also required removing the type check from the beginning of getMaskedTypeForICmpPair, but I believe that's ok because we still have to find two values from the input to each icmp that are equal before we'll do any transformation. So the type check was really just serving as an early out.

There was one user of decomposeBitTestICmp that didn't want to look through truncates, so I've added a flag to prevent that behavior when necessary.

Differential Revision: https://reviews.llvm.org/D37158

llvm-svn: 312382
2017-09-01 21:27:34 +00:00
Craig Topper c5e818e341 [InstCombine] Add tests to show missed opportunities to combine bit tests hidden by a sign compare and a truncate. NFC
llvm-svn: 311784
2017-08-25 17:14:35 +00:00
Sanjay Patel 3e9e5ccf7c [InstCombine] update to use FileCheck
Also, remove unnecessary function attributes, parameters, and comments.
It looks like at least some of these tests are not minimal though...

llvm-svn: 282620
2016-09-28 19:10:16 +00:00
Chandler Carruth ff123d5c63 Fix the remaining TCL-style quotes found in the testsuite. This is
another mechanical change accomplished though the power of terrible Perl
scripts.

I have manually switched some "s to 's to make escaping simpler.

While I started this to fix tests that aren't run in all configurations,
the massive number of tests is due to a really frustrating fragility of
our testing infrastructure: things like 'grep -v', 'not grep', and
'expected failures' can mask broken tests all too easily.

Essentially, I'm deeply disturbed that I can change the testsuite so
radically without causing any change in results for most platforms. =/

llvm-svn: 159547
2012-07-02 19:09:46 +00:00
Owen Anderson 3fe002dfb5 Generalize instcombine's support for combining multiple bit checks into a single test. Patch by Dirk Steinke!
llvm-svn: 113423
2010-09-08 22:16:17 +00:00
Owen Anderson 8f306a779b Re-apply the infamous r108614, with a fix pointed out by Dirk Steinke.
llvm-svn: 110036
2010-08-02 09:32:13 +00:00
Daniel Dunbar 0b636a24c7 Speculatively revert r108614, "Another attempt at getting the clang self-host to
like my instcombine patch.", in an attempt to fix Clang i386 bootstrap.
 - Also PR7719.

llvm-svn: 109953
2010-07-31 19:51:11 +00:00
Owen Anderson 7d2818b073 Another attempt at getting the clang self-host to like my instcombine patch.
llvm-svn: 108614
2010-07-17 06:56:35 +00:00
Eric Christopher 15a81cddb4 Also revert 108422, it's causing some test failures.
Working on testcases for Owen.

llvm-svn: 108494
2010-07-16 01:36:12 +00:00
Owen Anderson 7151dfd48a Reapply r108378, with bugfixes, testcase, and improved comment formatting.
This now passes LIT, nighty test, and llvm-gcc bootstrap on my machine.

llvm-svn: 108422
2010-07-15 15:00:23 +00:00