Commit Graph

7 Commits

Author SHA1 Message Date
Sanjay Patel b696b771bf [CGP] add test for unsigned subtract of 1 with overflow; NFC
llvm-svn: 353179
2019-02-05 15:27:40 +00:00
Sanjay Patel 738e17b5df [CGP] fix bogus test names/comments; NFC
Inverted operand 0 and operand 1.

llvm-svn: 353106
2019-02-04 22:37:05 +00:00
Sanjay Patel 1f9e23e3cc [CGP] add tests for usubo; NFC
llvm-svn: 353103
2019-02-04 22:27:08 +00:00
Sanjay Patel c00bdab4c8 [CGP] use IRBuilder to simplify code
This is no-functional-change-intended although there could
be intermediate variations caused by a difference in the
debug info produced by setting that from the builder's 
insertion point. 

I'm updating the IR test file associated with this code just
to show that the naming differences from using the builder
are visible.

The motivation for adding a helper function is that we are
likely to extend this code to deal with other overflow ops.

llvm-svn: 353056
2019-02-04 16:30:46 +00:00
Sanjay Patel 84ceae6048 [CGP] adjust target constraints for forming uaddo
There are 2 changes visible here:
1. There's no reason to limit this transform based on number
   of condition registers. That diff allows PPC to produce 
   slightly better (dot-instructions should be generally good) 
   code.
   Note: someone that cares about PPC codegen might want to 
   look closer at that output because it seems like we could
   still improve this.

2. We (probably?) should not bother trying to form uaddo (or
   other overflow ops) when there's no target support for such
   an op. This goes beyond checking whether the op is expanded
   because both PPC and AArch64 show better codegen for standard
   types regardless of whether the op is legal/custom.

llvm-svn: 353001
2019-02-03 17:53:09 +00:00
Sanjay Patel 837552fe9f [PatternMatch] add special-case uaddo matching for increment-by-one (2nd try)
This is the most important uaddo problem mentioned in PR31754:
https://bugs.llvm.org/show_bug.cgi?id=31754
...but that was overcome in x86 codegen with D57637.

That patch also corrects the inc vs. add regressions seen with the  previous attempt at this.

Still, we want to make this matcher complete, so we can potentially canonicalize the pattern 
even if it's an 'add 1' operation.
Pattern matching, however, shouldn't assume that we have canonicalized IR, so we match 4 
commuted variants of uaddo.

There's also a test with a crazy type to show that the existing CGP transform based on this 
matcher is not limited by target legality checks.

I'm not sure if the Hexagon diff means the test is no longer testing what it intended to
test, but that should be solvable in a follow-up.

Differential Revision: https://reviews.llvm.org/D57516

llvm-svn: 352998
2019-02-03 16:16:48 +00:00
Sanjay Patel b961bd68f0 [CGP] move test file to prevent bot failures
The test specifiies the triple, so it needs to be in the
x86 directory in case a bot has been configured without
the x86 target.

llvm-svn: 352992
2019-02-03 14:19:45 +00:00