Commit Graph

25 Commits

Author SHA1 Message Date
Benjamin Kramer
9c1df9164c InstCombine: Strength reduce sadd.with.overflow into a regular nsw add if we can prove that it cannot overflow.
PR20194

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212331 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-04 10:22:21 +00:00
Stephen Lin
39f4e8d9cc Update Transforms tests to use CHECK-LABEL for easier debugging. No functionality change.
This update was done with the following bash script:

  find test/Transforms -name "*.ll" | \
  while read NAME; do
    echo "$NAME"
    if ! grep -q "^; *RUN: *llc" $NAME; then
      TEMP=`mktemp -t temp`
      cp $NAME $TEMP
      sed -n "s/^define [^@]*@\([A-Za-z0-9_]*\)(.*$/\1/p" < $NAME | \
      while read FUNC; do
        sed -i '' "s/;\(.*\)\([A-Za-z0-9_]*\):\( *\)@$FUNC\([( ]*\)\$/;\1\2-LABEL:\3@$FUNC(/g" $TEMP
      done
      mv $TEMP $NAME
    fi
  done


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186268 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-14 01:42:54 +00:00
Andrew Trick
d2bcda7706 Revert "Have InstCombine call SipmlifyCall when handling calls. Test case included."
This reverts commit 3854a5d90f.

This causes a clang unit test to hang: vtable-available-externally.cpp.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@174692 91177308-0d34-0410-b5e6-96231b3b80d8
2013-02-08 01:55:39 +00:00
Michael Ilseman
3854a5d90f Have InstCombine call SipmlifyCall when handling calls. Test case included.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@174675 91177308-0d34-0410-b5e6-96231b3b80d8
2013-02-07 23:01:35 +00:00
Benjamin Kramer
e574246489 ConstantFolding: Add a missing folding that leads to a miscompile.
We use constant folding to see if an intrinsic evaluates to the same value as a
constant that we know. If we don't take the undefinedness into account we get a
value that doesn't match the actual implementation, and miscompiled code.

This was uncovered by Chandler's simplifycfg changes.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@173356 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-24 16:28:28 +00:00
Dmitri Gribenko
fbfb1b286f Tests: rewrite 'opt ... %s' to 'opt ... < %s' so that opt does not emit a ModuleID
This is done to avoid odd test failures, like the one fixed in r171243.

My previous regex was not good enough to find these.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@171343 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-01 13:57:25 +00:00
Chandler Carruth
d62414c654 Add an explicit test that we now fold cttz.i32(..., true) >> 5 -> 0.
This is a result of Benjamin's work on ValueTracking.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@147259 91177308-0d34-0410-b5e6-96231b3b80d8
2011-12-24 22:34:15 +00:00
Benjamin Kramer
009da05e75 ComputeMaskedBits: Make knownzero computation more aggressive for ctlz with undef zero.
unsigned foo(unsigned x) { return 31 - __builtin_clz(x); }
now compiles into a single "bsrl" instruction on x86.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@147255 91177308-0d34-0410-b5e6-96231b3b80d8
2011-12-24 17:31:46 +00:00
Chandler Carruth
ddbc274169 Manually upgrade the test suite to specify the flag to cttz and ctlz.
I followed three heuristics for deciding whether to set 'true' or
'false':

- Everything target independent got 'true' as that is the expected
  common output of the GCC builtins.
- If the target arch only has one way of implementing this operation,
  set the flag in the way that exercises the most of codegen. For most
  architectures this is also the likely path from a GCC builtin, with
  'true' being set. It will (eventually) require lowering away that
  difference, and then lowering to the architecture's operation.
- Otherwise, set the flag differently dependending on which target
  operation should be tested.

Let me know if anyone has any issue with this pattern or would like
specific tests of another form. This should allow the x86 codegen to
just iteratively improve as I teach the backend how to differentiate
between the two forms, and everything else should remain exactly the
same.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@146370 91177308-0d34-0410-b5e6-96231b3b80d8
2011-12-12 11:59:10 +00:00
Chris Lattner
d2bf432b2b Upgrade syntax of tests using volatile instructions to use 'load volatile' instead of 'volatile load', which is archaic.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@145171 91177308-0d34-0410-b5e6-96231b3b80d8
2011-11-27 06:54:59 +00:00
Eli Friedman
f03bb260c9 Move "atomic" and "volatile" designations on instructions after the opcode
of the instruction.

Note that this change affects the existing non-atomic load and store
instructions; the parser now accepts both forms, and the change is noted
in the release notes.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@137527 91177308-0d34-0410-b5e6-96231b3b80d8
2011-08-12 22:50:01 +00:00
Chris Lattner
d589099eec make the asmparser reject function and type redefinitions. 'Merging' hasn't been
needed since llvm-gcc 3.4 days.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@133248 91177308-0d34-0410-b5e6-96231b3b80d8
2011-06-17 07:06:44 +00:00
Benjamin Kramer
cd89d4d524 Revert "InstCombine: Turn mul.with.overflow(X, 2) into the cheaper add.with.overflow(X, X)"
It's better to do this in codegen, mul.with.overflow(X, 2) is more canonical because it has only one use on "X".

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@131798 91177308-0d34-0410-b5e6-96231b3b80d8
2011-05-21 18:31:42 +00:00
Benjamin Kramer
c21b205f93 InstCombine: Turn mul.with.overflow(X, 2) into the cheaper add.with.overflow(X, X)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@131789 91177308-0d34-0410-b5e6-96231b3b80d8
2011-05-21 09:22:06 +00:00
Eli Friedman
59f15918c2 More instcombine cleanup aimed towards improving debug line info.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@131559 91177308-0d34-0410-b5e6-96231b3b80d8
2011-05-18 19:57:14 +00:00
Benjamin Kramer
6b96fe7e14 InstCombine: Turn umul_with_overflow into mul nuw if we can prove that it cannot overflow.
This happens a lot in clang-compiled C++ code because it adds overflow checks to operator new[]:
  unsigned *foo(unsigned n) { return new unsigned[n]; }
We can optimize away the overflow check on 64 bit targets because (uint64_t)n*4 cannot overflow.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@127418 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-10 18:40:14 +00:00
Chris Lattner
a34b3cf953 X86 supports i8/i16 overflow ops (except i8 multiplies), we should
generate them.  

Now we compile:

define zeroext i8 @X(i8 signext %a, i8 signext %b) nounwind ssp {
entry:
  %0 = tail call %0 @llvm.sadd.with.overflow.i8(i8 %a, i8 %b)
  %cmp = extractvalue %0 %0, 1
  br i1 %cmp, label %if.then, label %if.end

into:

_X:                                     ## @X
## BB#0:                                ## %entry
	subl	$12, %esp
	movb	16(%esp), %al
	addb	20(%esp), %al
	jo	LBB0_2

Before we were generating:

_X:                                     ## @X
## BB#0:                                ## %entry
	pushl	%ebp
	movl	%esp, %ebp
	subl	$8, %esp
	movb	12(%ebp), %al
	testb	%al, %al
	setge	%cl
	movb	8(%ebp), %dl
	testb	%dl, %dl
	setge	%ah
	cmpb	%cl, %ah
	sete	%cl
	addb	%al, %dl
	testb	%dl, %dl
	setge	%al
	cmpb	%al, %ah
	setne	%al
	andb	%cl, %al
	testb	%al, %al
	jne	LBB0_2




git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122186 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-19 20:03:11 +00:00
Chris Lattner
26b482d7a7 optimize uadd(x, cst) into a comparison when the normal
result is dead.  This is required for my next patch to not
regress the testsuite.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122181 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-19 19:35:32 +00:00
Eli Friedman
4fffb345ed PR7853: fix a silly mistake introduced in r101899, and add a test to make sure
it doesn't regress again.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@110597 91177308-0d34-0410-b5e6-96231b3b80d8
2010-08-09 20:49:43 +00:00
Chris Lattner
818ff34bc0 implement a simple instcombine xform that has been in the
readme forever.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@94318 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-23 18:49:30 +00:00
Chris Lattner
033574074d optimize comparisons against cttz/ctlz/ctpop, patch by Alastair Lynn!
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@92745 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-05 18:09:56 +00:00
Chris Lattner
16507fe9fd optimize cttz and ctlz when we can prove something about the
leading/trailing bits.  Patch by Alastair Lynn!


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@92706 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-05 07:23:56 +00:00
Chris Lattner
d27f911b23 add a few trivial instcombines for llvm.powi.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@92383 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-01 01:52:15 +00:00
Chris Lattner
cd188e9665 add testcases for the foo_with_overflow op xforms added recently and
fix bugs exposed by the tests.  Testcases from Alastair Lynn!



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90056 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-29 02:57:29 +00:00
Chris Lattner
7e606e2e98 if a 'with overflow' intrinsic just has the normal result used, simplify
it to a normal binop.  Patch by Alastair Lynn, testcase by me.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86524 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-09 07:07:56 +00:00