Commit Graph

12 Commits

Author SHA1 Message Date
Hans Wennborg a468601e0e [X86] Re-enable conditional tail calls and fix PR31257.
This reverts r294348, which removed support for conditional tail calls
due to the PR above. It fixes the PR by marking live registers as
implicitly used and defined by the now predicated tailcall. This is
similar to how IfConversion predicates instructions.

Differential Revision: https://reviews.llvm.org/D29856

llvm-svn: 295262
2017-02-16 00:04:05 +00:00
Hans Wennborg 819e3e02a9 [X86] Disable conditional tail calls (PR31257)
They are currently modelled incorrectly (as calls, which clobber
registers, confusing e.g. Machine Copy Propagation).

Reverting until we figure out the proper solution.

llvm-svn: 294348
2017-02-07 20:37:45 +00:00
Hans Wennborg 6ecf619be9 X86: Fold tail calls into conditional branches also for 64-bit (PR26302)
This extends the optimization in r280832 to also work for 64-bit. The only
quirk is that we can't do this for 64-bit Windows (yet).

Differential Revision: https://reviews.llvm.org/D24423

llvm-svn: 281113
2016-09-09 22:37:27 +00:00
David Blaikie a79ac14fa6 [opaque pointer type] Add textual IR support for explicit type parameter to load instruction
Essentially the same as the GEP change in r230786.

A similar migration script can be used to update test cases, though a few more
test case improvements/changes were required this time around: (r229269-r229278)

import fileinput
import sys
import re

pat = re.compile(r"((?:=|:|^)\s*load (?:atomic )?(?:volatile )?(.*?))(| addrspace\(\d+\) *)\*($| *(?:%|@|null|undef|blockaddress|getelementptr|addrspacecast|bitcast|inttoptr|\[\[[a-zA-Z]|\{\{).*$)")

for line in sys.stdin:
  sys.stdout.write(re.sub(pat, r"\1, \2\3*\4", line))

Reviewers: rafael, dexonsmith, grosser

Differential Revision: http://reviews.llvm.org/D7649

llvm-svn: 230794
2015-02-27 21:17:42 +00:00
Matt Arsenault 22b4c256e1 Enable (sext x) == C --> x == (trunc C) combine
Extend the existing code which handles this for zext. This makes this
more useful for targets with ZeroOrNegativeOne BooleanContent and
obsoletes a custom combine SI uses for i1 setcc (sext(i1), 0, setne)
since the constant will now be shrunk to i1.

llvm-svn: 224691
2014-12-21 16:48:42 +00:00
Jim Grosbach 860934a924 X86: Perform integer comparisons at i32 or larger.
Utilizing the 8 and 16 bit comparison instructions, even when an input can
be folded into the comparison instruction itself, is typically not worth it.
There are too many partial register stalls as a result, leading to significant
slowdowns. By always performing comparisons on at least 32-bit
registers, performance of the calculation chain leading to the
comparison improves. Continue to use the smaller comparisons when
minimizing size, as that allows better folding of loads into the
comparison instructions.

rdar://15386341

llvm-svn: 195496
2013-11-22 19:57:47 +00:00
Stephen Lin f799e3f944 Convert CodeGen/*/*.ll tests to use the new CHECK-LABEL for easier debugging. No functionality change and all tests pass after conversion.
This was done with the following sed invocation to catch label lines demarking function boundaries:
    sed -i '' "s/^;\( *\)\([A-Z0-9_]*\):\( *\)test\([A-Za-z0-9_-]*\):\( *\)$/;\1\2-LABEL:\3test\4:\5/g" test/CodeGen/*/*.ll
which was written conservatively to avoid false positives rather than false negatives. I scanned through all the changes and everything looks correct.

llvm-svn: 186258
2013-07-13 20:38:47 +00:00
Benjamin Kramer c7332b2796 DAGCombiner: Don't drop extension behavior when shrinking a load when unsafe.
ReduceLoadWidth unconditionally drops extensions from loads. Limit it to the
case when all of the bits the extension would otherwise produce are dropped by
the shrink. It would be possible to shrink the load in more cases by merging
the extensions, but this isn't trivial and a very rare case. I left a TODO for
that case.

Fixes PR16551.

llvm-svn: 185755
2013-07-06 14:05:09 +00:00
Benjamin Kramer 8aaf197990 DAGCombine: Avoid an edge case where it tried to create an i0 type for (x & 0) == 0.
Fixes PR16083.

llvm-svn: 182357
2013-05-21 08:51:09 +00:00
Benjamin Kramer fc88c3761f DAGCombine: Also shrink eq compares where the constant is exactly as large as the smaller type.
if ((x & 255) == 255)

before: movzbl  %al, %eax
        cmpl  $255, %eax

after:  cmpb  $-1, %al
llvm-svn: 182038
2013-05-16 18:47:58 +00:00
NAKAMURA Takumi 576273cf56 test/CodeGen/X86/shrink-compare.ll: Relax expressions for Win64.
llvm-svn: 130039
2011-04-23 00:15:45 +00:00
Benjamin Kramer 341c11da3b DAGCombine: fold "(zext x) == C" into "x == (trunc C)" if the trunc is lossless.
On x86 this allows to fold a load into the cmp, greatly reducing register pressure.
  movzbl	(%rdi), %eax
  cmpl	$47, %eax
->
  cmpb	$47, (%rdi)

This shaves 8k off gcc.o on i386. I'll leave applying the patch in README.txt to Chris :)

llvm-svn: 130005
2011-04-22 18:47:44 +00:00