Commit Graph

13 Commits

Author SHA1 Message Date
Nirav Dave 3264c1bdf6 [DAG, X86] Revert r327197 "Revert r327170, r327171, r327172"
Reland ISel cycle checking improvements after simplifying node id
invariant traversal and correcting typo.

llvm-svn: 327898
2018-03-19 20:19:46 +00:00
Nirav Dave 5f0ab71b62 Revert "[DAG, X86] Revert r327197 "Revert r327170, r327171, r327172""
as it times out building test-suite on PPC.

llvm-svn: 327778
2018-03-17 19:24:54 +00:00
Nirav Dave 982d3a56ea [DAG, X86] Revert r327197 "Revert r327170, r327171, r327172"
Reland ISel cycle checking improvements after simplifying and reducing
node id invariant traversal.

llvm-svn: 327777
2018-03-17 17:42:10 +00:00
Nirav Dave 042678bd55 Revert: r327172 "Correct load-op-store cycle detection analysis"
r327171 "Improve Dependency analysis when doing multi-node Instruction Selection"
        r328170 "[DAG] Enforce stricter NodeId invariant during Instruction selection"

Reverting patch as NodeId invariant change is causing pathological
increases in compile time on PPC

llvm-svn: 327197
2018-03-10 02:16:15 +00:00
Nirav Dave d668f69ee7 Improve Dependency analysis when doing multi-node Instruction Selection
Relanding after fixing NodeId Invariant.

Cleanup cycle/validity checks in ISel (IsLegalToFold,
HandleMergeInputChains) and X86 (isFusableLoadOpStore). Now do a full
search for cycles / dependencies pruning the search when topological
property of NodeId allows.

As part of this propogate the NodeId-based cutoffs to narrow
hasPreprocessorHelper searches.

Reviewers: craig.topper, bogner

Subscribers: llvm-commits, hiraditya

Differential Revision: https://reviews.llvm.org/D41293

llvm-svn: 327171
2018-03-09 20:57:42 +00:00
Chandler Carruth a1d6107b14 [DAG, X86] Revert r324797, r324491, and r324359.
Sadly, r324359 caused at least PR36312. There is a patch out for review
but it seems to be taking a bit and we've already had these crashers in
tree for too long. We're hitting this PR in real code now and are
blocked on shipping new compilers as a consequence so I'm reverting us
back to green.

Sorry for the churn due to the stacked changes that I had to revert. =/

llvm-svn: 325420
2018-02-17 02:26:25 +00:00
Nirav Dave 27721e8617 [DAG, X86] Improve Dependency analysis when doing multi-node
Instruction Selection

Cleanup cycle/validity checks in ISel (IsLegalToFold,
HandleMergeInputChains) and X86 (isFusableLoadOpStore). Now do a full
search for cycles / dependencies pruning the search when topological
property of NodeId allows.

As part of this propogate the NodeId-based cutoffs to narrow
hasPreprocessorHelper searches.

Reviewers: craig.topper, bogner

Subscribers: llvm-commits, hiraditya

Differential Revision: https://reviews.llvm.org/D41293

llvm-svn: 324359
2018-02-06 16:14:29 +00:00
Francis Visoiu Mistrih 25528d6de7 [CodeGen] Unify MBB reference format in both MIR and debug output
As part of the unification of the debug format and the MIR format, print
MBB references as '%bb.5'.

The MIR printer prints the IR name of a MBB only for block definitions.

* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" \) -type f -print0 | xargs -0 sed -i '' -E 's/BB#" << ([a-zA-Z0-9_]+)->getNumber\(\)/" << printMBBReference(*\1)/g'
* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" \) -type f -print0 | xargs -0 sed -i '' -E 's/BB#" << ([a-zA-Z0-9_]+)\.getNumber\(\)/" << printMBBReference(\1)/g'
* find . \( -name "*.txt" -o -name "*.s" -o -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" \) -type f -print0 | xargs -0 sed -i '' -E 's/BB#([0-9]+)/%bb.\1/g'
* grep -nr 'BB#' and fix

Differential Revision: https://reviews.llvm.org/D40422

llvm-svn: 319665
2017-12-04 17:18:51 +00:00
Sanjay Patel 169dae70a6 [x86] use more shift or LEA for select-of-constants (2nd try)
The previous rev (r310208) failed to account for overflow when subtracting the
constants to see if they're suitable for shift/lea. This version add a check
for that and more test were added in r310490.

We can convert any select-of-constants to math ops:
http://rise4fun.com/Alive/d7d

For this patch, I'm enhancing an existing x86 transform that uses fake multiplies
(they always become shl/lea) to avoid cmov or branching. The current code misses
cases where we have a negative constant and a positive constant, so this is just
trying to plug that hole.

The DAGCombiner diff prevents us from hitting a terrible inefficiency: we can start
with a select in IR, create a select DAG node, convert it into a sext, convert it
back into a select, and then lower it to sext machine code.

Some notes about the test diffs:

1. 2010-08-04-MaskedSignedCompare.ll - We were creating control flow that didn't exist in the IR.
2. memcmp.ll - Choose -1 or 1 is the case that got me looking at this again. We could avoid the 
   push/pop in some cases if we used 'movzbl %al' instead of an xor on a different reg? That's a 
   post-DAG problem though.
3. mul-constant-result.ll - The trade-off between sbb+not vs. setne+neg could be addressed if
   that's a regression, but those would always be nearly equivalent.
4. pr22338.ll and sext-i1.ll - These tests have undef operands, so we don't actually care about these diffs.
5. sbb.ll - This shows a win for what is likely a common case: choose -1 or 0.
6. select.ll - There's another borderline case here: cmp+sbb+or vs. test+set+lea? Also, sbb+not vs. setae+neg shows up again.
7. select_const.ll - These are motivating cases for the enhancement; replace cmov with cheaper ops.

Assembly differences between movzbl and xor to avoid a partial reg stall are caused later by the X86 Fixup SetCC pass.

Differential Revision: https://reviews.llvm.org/D35340

llvm-svn: 310717
2017-08-11 15:44:14 +00:00
Sanjay Patel 807f92b8ff [x86] revert r310208 to investigate test-suite failures (PR34105 / PR34097)
llvm-svn: 310264
2017-08-07 15:47:48 +00:00
Sanjay Patel a923c2ee95 [x86] use more shift or LEA for select-of-constants
We can convert any select-of-constants to math ops:
http://rise4fun.com/Alive/d7d

For this patch, I'm enhancing an existing x86 transform that uses fake multiplies 
(they always become shl/lea) to avoid cmov or branching. The current code misses 
cases where we have a negative constant and a positive constant, so this is just 
trying to plug that hole.

The DAGCombiner diff prevents us from hitting a terrible inefficiency: we can start 
with a select in IR, create a select DAG node, convert it into a sext, convert it 
back into a select, and then lower it to sext machine code.

Some notes about the test diffs:

1. 2010-08-04-MaskedSignedCompare.ll - We were creating control flow that didn't exist in the IR.
2. memcmp.ll - Choose -1 or 1 is the case that got me looking at this again. I 
   think we could avoid the push/pop in some cases if we used 'movzbl %al' instead of an xor on 
   a different reg? That's a post-DAG problem though.
3. mul-constant-result.ll - The trade-off between sbb+not vs. setne+neg could be addressed if 
   that's a regression, but I think those would always be nearly equivalent.
4. pr22338.ll and sext-i1.ll - These tests have undef operands, so I don't think we actually care about these diffs.
5. sbb.ll - This shows a win for what I think is a common case: choose -1 or 0.
6. select.ll - There's another borderline case here: cmp+sbb+or vs. test+set+lea? Also, sbb+not vs. setae+neg shows up again.
7. select_const.ll - These are motivating cases for the enhancement; replace cmov with cheaper ops.

Assembly differences between movzbl and xor to avoid a partial reg stall are caused later by the X86 Fixup SetCC pass.

Differential Revision: https://reviews.llvm.org/D35340

llvm-svn: 310208
2017-08-06 16:27:07 +00:00
Sanjay Patel 563e5afa0e [x86] remove overridden target settings in test; NFC
r306109 was supposed to make this change, but I committed the wrong version.

llvm-svn: 306110
2017-06-23 15:06:30 +00:00
Sanjay Patel 8e06df4303 [x86] rename test file and auto-generate complete checks; NFC
The command-line params override the target setting in the file itself, so delete that.
Also, remove the cpu and arch because those don't matter and neither does the OS specification in the triple.

llvm-svn: 306109
2017-06-23 14:58:21 +00:00