Commit Graph

60 Commits

Author SHA1 Message Date
Benjamin Kramer
7ebdc37d2b InstCombine: APFloat can't perform arithmetic on PPC double doubles, don't even try.
Thanks Eli!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@128676 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-31 21:35:49 +00:00
Benjamin Kramer
00e00d693c InstCombine: Fix transform to use the swapped predicate.
Thanks Frits!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@128628 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-31 10:46:03 +00:00
Benjamin Kramer
68b4bd0a63 InstCombine: fold fcmp (fneg x), (fneg y) -> fcmp x, y
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@128627 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-31 10:12:22 +00:00
Benjamin Kramer
0db50189dc InstCombine: fold fcmp pred (fneg x), C -> fcmp swap(pred) x, -C
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@128626 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-31 10:12:15 +00:00
Benjamin Kramer
b194bdc03b InstCombine: Shrink "fcmp (fpext x), C" to "fcmp x, C" if C can be losslessly converted to the type of x.
Fixes PR9592.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@128625 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-31 10:12:07 +00:00
Benjamin Kramer
cd0274ca18 InstCombine: fold fcmp (fpext x), (fpext y) -> fcmp x, y.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@128624 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-31 10:11:58 +00:00
Nick Lewycky
dcf77575d2 Reorder comments to put them the right way around.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@127220 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-08 06:29:47 +00:00
Nick Lewycky
d01f50f42c ConstantInt has some getters which return ConstantInt's or ConstantVector's of
the value splatted into every element. Extend this to getTrue and getFalse which
by providing new overloads that take Types that are either i1 or <N x i1>. Use
it in InstCombine to add vector support to some code, fixing PR8469!


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@127116 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-06 03:36:19 +00:00
Nick Lewycky
58bfcdbcf6 Thread comparisons over udiv/sdiv/ashr/lshr exact and lshr nuw/nsw whenever
possible. This goes into instcombine and instsimplify because instsimplify
doesn't need to check hasOneUse since it returns (almost exclusively) constants.

This fixes PR9343 #4 #5 and #8!


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@127064 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-05 05:19:11 +00:00
Nick Lewycky
9feda1730c Try once again to optimize "icmp (srem X, Y), Y" by turning the comparison into
true/false or "icmp slt/sge Y, 0".


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@127063 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-05 04:28:48 +00:00
Nick Lewycky
3dc7e49c70 srem doesn't actually have the same resulting sign as its numerator, you could
also have a zero when numerator = denominator. Reverts parts of r126635 and
r126637.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@126644 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-28 09:17:39 +00:00
Nick Lewycky
b042f8e969 Teach InstCombine to fold "(shr exact X, Y) == 0" --> X == 0, fixing #1 from
PR9343.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@126643 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-28 08:31:40 +00:00
Nick Lewycky
d8d1584c13 The sign of an srem instruction is the sign of its dividend (the first
argument), regardless of the divisor. Teach instcombine about this and fix
test7 in PR9343!


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@126635 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-28 06:20:05 +00:00
Duncan Sands
39a7de72c8 Add some transforms of the kind X-Y>X -> 0>Y which are valid when there is no
overflow.  These subsume some existing equality transforms, so zap those.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@125843 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-18 16:25:37 +00:00
Duncan Sands
a77243300b Transform "A + B >= A + C" into "B >= C" if the adds do not wrap. Likewise for some
variations (some of these were already present so I unified the code).  Spotted by my
auto-simplifier as occurring a lot.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@125734 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-17 07:46:37 +00:00
Chris Lattner
e5116f840e remove a now-unneccesary cast.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@125464 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-13 18:30:09 +00:00
Chris Lattner
bb75d337c4 implement instcombine folding for things like (x >> c) < 42.
We were previously simplifying divisions, but not right shifts!


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@125454 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-13 08:07:21 +00:00
Chris Lattner
74542aa500 refactor some code out into a helper method.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@125451 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-13 07:43:07 +00:00
Benjamin Kramer
b6c8cb4422 Also fold (A+B) == A -> B == 0 when the add is commuted.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@125411 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-11 21:46:48 +00:00
Chris Lattner
b20c0b5092 Enhance the "compare with shift" and "compare with div"
optimizations to be much more aggressive in the face of
exact/nsw/nuw div and shifts.  For example, these (which
are the same except the first is 'exact' sdiv:

define i1 @sdiv_icmp4_exact(i64 %X) nounwind {
  %A = sdiv exact i64 %X, -5   ; X/-5 == 0 --> x == 0
  %B = icmp eq i64 %A, 0
  ret i1 %B
}

define i1 @sdiv_icmp4(i64 %X) nounwind {
  %A = sdiv i64 %X, -5   ; X/-5 == 0 --> x == 0
  %B = icmp eq i64 %A, 0
  ret i1 %B
}

compile down to:

define i1 @sdiv_icmp4_exact(i64 %X) nounwind {
  %1 = icmp eq i64 %X, 0
  ret i1 %1
}

define i1 @sdiv_icmp4(i64 %X) nounwind {
  %X.off = add i64 %X, 4
  %1 = icmp ult i64 %X.off, 9
  ret i1 %1
}

This happens when you do something like:
  (ptr1-ptr2) == 42

where the pointers are pointers to non-unit types.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@125266 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-10 05:23:05 +00:00
Anders Carlsson
77bc49e5e2 Recognize and simplify
(A+B) == A  ->  B == 0
A == (A+B)  ->  B == 0



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124567 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-30 22:01:13 +00:00
Duncan Sands
9d32f60a6f At -O123 the early-cse pass is run before instcombine has run. According to my
auto-simplier the transform most missed by early-cse is (zext X) != 0 -> X != 0.
This patch adds this transform and some related logic to InstructionSimplify
and removes some of the logic from instcombine (unfortunately not all because
there are several situations in which instcombine can improve things by making
new instructions, whereas instsimplify is not allowed to do this).  At -O2 this
often results in more than 15% more simplifications by early-cse, and results in
hundreds of lines of bitcode being eliminated from the testsuite.  I did see some
small negative effects in the testsuite, for example a few additional instructions
in three programs.  One program, 483.xalancbmk, got an additional 35 instructions,
which seems to be due to a function getting an additional instruction and then
being inlined all over the place.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123911 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-20 13:21:55 +00:00
Chris Lattner
9922ccf4b4 remove the AllowAggressive argument to FoldOpIntoPhi. It is forced to false in the
first line of the function because it isn't a good idea, even for compares.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123566 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-16 05:14:26 +00:00
Chris Lattner
27a98482bd fix typo
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123516 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-15 05:42:47 +00:00
Chris Lattner
fdb5b01df4 Catch ~x < cst just like ~x < ~y, we currently handle this through
means that are about to disappear.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123515 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-15 05:41:33 +00:00
Owen Anderson
a33b6254bb Remove dead variable, const-ref-ize an APInt.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123248 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-11 18:26:37 +00:00
Owen Anderson
da1c122da5 Fix a random missed optimization by making InstCombine more aggressive when determining which bits are demanded by
a comparison against a constant.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123203 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-11 00:36:45 +00:00
Chris Lattner
e5cbdca3bd recognize an unsigned add with overflow idiom into uadd.
This resolves a README entry and technically resolves PR4916,
but we still get poor code for the testcase in that PR because
GVN isn't CSE'ing uadd with add, filed as PR8817.

Previously we got:

_test7:                                 ## @test7
	addq	%rsi, %rdi
	cmpq	%rdi, %rsi
	movl	$42, %eax
	cmovaq	%rsi, %rax
	ret

Now we get:

_test7:                                 ## @test7
	addq	%rsi, %rdi
	movl	$42, %eax
	cmovbq	%rsi, %rax
	ret



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122182 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-19 19:37:52 +00:00
Chris Lattner
0fe80bbbb6 use IC.ReplaceInstUsesWith instead of a raw RAUW so that uses of
the old thing end up on the instcombine worklist.  Not doing this
can cause an extra top-level iteration of instcombine, burning
compile time.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122179 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-19 18:38:44 +00:00
Chris Lattner
0a62474830 generalize the sadd creation code to not require that the
sadd formed is half the size of the original type. We can
now compile this into a sadd.i8:

unsigned char X(char a, char b) {
  int res = a+b;
  if ((unsigned )(res+128) > 255U)
    abort();
  return res;
}




git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122178 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-19 18:35:09 +00:00
Chris Lattner
dd7e837374 fix another miscompile in the llvm.sadd formation logic: it wasn't
checking to see if the high bits of the original add result were dead.
Inserting a smaller add and zexting back to that size is not good enough.

This is likely to be the fix for 8816.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122177 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-19 18:22:06 +00:00
Chris Lattner
368397bb7d fix a bug (possibly 8816) in the sadd forming xform: it isn't
profitable (or safe) to promote code when the add-with-constant
has other uses.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122175 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-19 17:59:02 +00:00
Chris Lattner
f0f568b49e rework the code added in r122072 to pull it out to its own
helper function, clean up comments, and reduce indentation.
No functionality change.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122174 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-19 17:52:50 +00:00
Owen Anderson
e63dda51c2 Reapply r121905 (automatic synthesis of @llvm.sadd.with.overflow) with a fix for a bug that manifested itself
on the DragonEgg self-host bot.  Unfortunately, the testcase is pretty messy and doesn't reduce well due to
interactions with other parts of InstCombine.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122072 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-17 18:08:00 +00:00
Duncan Sands
ebef48ea4b Speculatively revert commit 121905 since it looks like it might have broken the
dragonegg self-host buildbot.  Original commit message:

Add an InstCombine transform to recognize instances of manual overflow-safe addition
(performing the addition in a wider type and explicitly checking for overflow), and
fold them down to intrinsics.  This currently only supports signed-addition, but could
be generalized if someone works out the magic constant formulas for other operations.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121965 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-16 09:40:54 +00:00
Owen Anderson
12984de314 Add an InstCombine transform to recognize instances of manual overflow-safe addition
(performing the addition in a wider type and explicitly checking for overflow), and
fold them down to intrinsics.  This currently only supports signed-addition, but could
be generalized if someone works out the magic constant formulas for other operations.

Fixes <rdar://problem/8558713>.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121905 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-15 22:32:38 +00:00
Jay Foad
40f8f6264d PR5207: Change APInt methods trunc(), sext(), zext(), sextOrTrunc() and
zextOrTrunc(), and APSInt methods extend(), extOrTrunc() and new method
trunc(), to be const and to return a new value instead of modifying the
object in place.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121120 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-07 08:25:19 +00:00
Jay Foad
7a874ddda0 PR5207: Rename overloaded APInt methods set(), clear(), flip() to
setAllBits(), setBit(unsigned), etc.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@120564 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-01 08:53:58 +00:00
Chris Lattner
79b967bd9f duncan's spider sense was right, I completely reversed the condition
on this instcombine xform.  This fixes a miscompilation of 403.gcc.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@119988 91177308-0d34-0410-b5e6-96231b3b80d8
2010-11-23 02:42:04 +00:00
Chris Lattner
75d8f599e7 optimize:
void a(int x) { if (((1<<x)&8)==0) b(); }

into "x != 3", which occurs over 100 times in 403.gcc but in no
other program in llvm-test.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@119922 91177308-0d34-0410-b5e6-96231b3b80d8
2010-11-21 06:44:42 +00:00
Eli Friedman
618898e933 PR7750: !CExpr->isNullValue() only properly computes whether CExpr is nonnull
if CExpr is a ConstantInt.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@109773 91177308-0d34-0410-b5e6-96231b3b80d8
2010-07-29 18:03:33 +00:00
Duncan Sands
3472766f9e Convert some tab stops into spaces.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@108130 91177308-0d34-0410-b5e6-96231b3b80d8
2010-07-12 08:16:59 +00:00
Gabor Greif
caf70b31b0 use ArgOperand API
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@106752 91177308-0d34-0410-b5e6-96231b3b80d8
2010-06-24 16:11:44 +00:00
Duncan Sands
1d9b973fd7 Teach instCombine to remove malloc+free if malloc's only uses are comparisons
to null.  Patch by Matti Niemenmaa.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@104871 91177308-0d34-0410-b5e6-96231b3b80d8
2010-05-27 19:09:06 +00:00
Eric Christopher
551754c495 Revert 101465, it broke internal OpenGL testing.
Probably the best way to know that all getOperand() calls have been handled
is to replace that API instead of updating.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@101579 91177308-0d34-0410-b5e6-96231b3b80d8
2010-04-16 23:37:20 +00:00
Gabor Greif
4ec2258ffb reapply r101434
with a fix for self-hosting

rotate CallInst operands, i.e. move callee to the back
of the operand array

the motivation for this patch are laid out in my mail to llvm-commits:
more efficient access to operands and callee, faster callgraph-construction,
smaller compiler binary


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@101465 91177308-0d34-0410-b5e6-96231b3b80d8
2010-04-16 15:33:14 +00:00
Gabor Greif
607a7ab3da back out r101423 and r101397, they break llvm-gcc self-host on darwin10
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@101434 91177308-0d34-0410-b5e6-96231b3b80d8
2010-04-16 01:16:20 +00:00
Gabor Greif
2ff961f668 reapply r101364, which has been backed out in r101368
with a fix

rotate CallInst operands, i.e. move callee to the back
of the operand array

the motivation for this patch are laid out in my mail to llvm-commits:
more efficient access to operands and callee, faster callgraph-construction,
smaller compiler binary


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@101397 91177308-0d34-0410-b5e6-96231b3b80d8
2010-04-15 20:51:13 +00:00
Gabor Greif
9ee1720811 back out r101364, as it trips the linux nightlybot on some clang C++ tests
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@101368 91177308-0d34-0410-b5e6-96231b3b80d8
2010-04-15 12:46:56 +00:00
Gabor Greif
165dac08d1 rotate CallInst operands, i.e. move callee to the back
of the operand array

the motivation for this patch are laid out in my mail to llvm-commits:
more efficient access to operands and callee, faster callgraph-construction,
smaller compiler binary


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@101364 91177308-0d34-0410-b5e6-96231b3b80d8
2010-04-15 10:49:53 +00:00