Commit Graph

9 Commits

Author SHA1 Message Date
Amaury Sechet 4b946916ac [DAGCombiner] Push truncate through adde when the carry isn't used.
Summary: As per title.

Reviewers: mkuper, spatel, bkramer, RKSimon, zvi

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D29528

llvm-svn: 294394
2017-02-08 00:32:36 +00:00
Daniel Jasper 84b3cc394d Revert "[DAGCombiner] (add X, (adde Y, 0, Carry)) -> (adde X, Y, Carry)"
This reverts commit r294186.

On an internal test, this triggers an out-of-memory error on PPC,
presumably because there is another dagcombine that does the exact
opposite triggering and endless loop consuming more and more memory.

Chandler has started at creating a reduced test case and we'll attach it
as soon as possible.

llvm-svn: 294288
2017-02-07 08:57:50 +00:00
Amaury Sechet 1d466f598e [DAGCombiner] (add X, (adde Y, 0, Carry)) -> (adde X, Y, Carry)
Summary: This is extracted from D29443 .

Reviewers: mkuper, spatel, RKSimon, zvi, bkramer

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D29564

llvm-svn: 294186
2017-02-06 14:28:39 +00:00
Amaury Sechet 143902c29f [DAGCombiner] Leverage add's commutativity
Summary: This avoid the need to duplicate all pattern and actually end up exposing some opportunity to optimize existing pattern that did not exists in both directions on an existing test case.

Reviewers: mkuper, spatel, bkramer, RKSimon, zvi

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D29541

llvm-svn: 294125
2017-02-05 14:22:20 +00:00
Amaury Sechet 2247458d17 Add test cases for (trunc adde) DAGCombiner patterns. NFC
llvm-svn: 294105
2017-02-04 22:53:07 +00:00
Amaury Sechet 0f7badc957 Add test cases for bug 31719. NFC
llvm-svn: 294080
2017-02-04 01:48:30 +00:00
Zvi Rackover a2a502b583 [X86] Reproducer for pr31719. NFC
llvm-svn: 293437
2017-01-29 17:57:26 +00:00
Benjamin Kramer 8665f8d916 Revert a part of r126557 which could create unschedulable DAGs.
llvm-svn: 134067
2011-06-29 13:47:25 +00:00
Benjamin Kramer 26691d9660 Add some DAGCombines for (adde 0, 0, glue), which are useful to optimize legalized code for large integer arithmetic.
1. Inform users of ADDEs with two 0 operands that it never sets carry
2. Fold other ADDs or ADDCs into the ADDE if possible

It would be neat if we could do the same thing for SETCC+ADD eventually, but we can't do that in target independent code.

llvm-svn: 126557
2011-02-26 22:48:07 +00:00