Commit Graph

814 Commits

Author SHA1 Message Date
Dan Gohman
0e19a3f89e Check in test changes that I accidentally left out of r72872.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@72875 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-04 18:22:31 +00:00
Evan Cheng
2ddb6f1440 Fix bug in FoldFCmp_IntToFP_Cst. If inttofp is a uintofp, use unsigned instead of signed integer constant.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@72300 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-22 23:10:53 +00:00
Dan Gohman
9004c8afd4 Teach ValueTracking a new way to analyze PHI nodes, and and teach
Instcombine to be more aggressive about using SimplifyDemandedBits
on shift nodes. This allows a shift to be simplified to zero in the
included test case.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@72204 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-21 02:28:33 +00:00
Chris Lattner
aab6ec49d2 calls in nothrow functions can be marked nothrow even if the callee
is not known to be nothrow.  This allows readnone/readonly functions
to be deleted even if we don't know whether the callee can throw.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@71676 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-13 17:39:14 +00:00
Dan Gohman
9a38e3e399 Revert 71165. It did more than just revert 71158 and it introduced
several regressions. The problem due to 71158 is now fixed.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@71176 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-07 19:46:24 +00:00
Bill Wendling
5b8479c385 Temporarily revert r71158. It was causing a failure during a full bootstrap:
checking for bcopy... no
checking for getc_unlocked... Assertion failed: (0 && "Unknown SCEV kind!"), function operator(), file /Volumes/Sandbox/Buildbot/llvm/full-llvm/build/llvmCore.roots/llvmCore~obj/src/lib/Analysis/ScalarEvolution.cpp, line 511.
/Volumes/Sandbox/Buildbot/llvm/full-llvm/build/llvmgcc42.roots/llvmgcc42~obj/src/libdecnumber/decUtility.c:360: internal compiler error: Abort trap
Please submit a full bug report,
with preprocessed source if appropriate.
See <URL:http://developer.apple.com/bugreporter> for instructions.
make[4]: *** [decUtility.o] Error 1
make[4]: *** Waiting for unfinished jobs....
Assertion failed: (0 && "Unknown SCEV kind!"), function operator(), file /Volumes/Sandbox/Buildbot/llvm/full-llvm/build/llvmCore.roots/llvmCore~obj/src/lib/Analysis/ScalarEvolution.cpp, line 511.
/Volumes/Sandbox/Buildbot/llvm/full-llvm/build/llvmgcc42.roots/llvmgcc42~obj/src/libdecnumber/decNumber.c:5591: internal compiler error: Abort trap
Please submit a full bug report,
with preprocessed source if appropriate.
See <URL:http://developer.apple.com/bugreporter> for instructions.
make[4]: *** [decNumber.o] Error 1
make[3]: *** [all-stage2-libdecnumber] Error 2
make[3]: *** Waiting for unfinished jobs....



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@71165 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-07 17:26:14 +00:00
Dan Gohman
704b6980b8 Constant-fold ptrtoint+add+inttoptr to gep when the pointer is an
array and the add is within range. This helps simplify expressions
expanded by ScalarEvolutionExpander.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@71158 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-07 14:24:56 +00:00
Dan Gohman
1c8491ecc7 Add several more icmp simplifications. Transform signed comparisons
into unsigned ones when the operands are known to have the same
sign bit value.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@70053 91177308-0d34-0410-b5e6-96231b3b80d8
2009-04-25 17:12:48 +00:00
Chris Lattner
266c7bbbbc Add a new "available_externally" linkage type. This is intended
to support C99 inline, GNU extern inline, etc.  Related bugzilla's
include PR3517, PR3100, & PR2933.  Nothing uses this yet, but it
appears to work.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@68940 91177308-0d34-0410-b5e6-96231b3b80d8
2009-04-13 05:44:34 +00:00
Chris Lattner
ddfa57bd7b Instcombine should not promote whole computation trees to "strange"
integer types, unless they are already strange.  This prevents it from
turning the code produced by SROA into crazy libcalls and stuff that 
the code generator can't handle.  In the attached example, the result
was an i96 multiply that caused the x86 backend to assert.

Note that if TargetData had an idea of what the legal types are for
a target that this could be used to stop instcombine from introducing
i64 muls, as Scott wanted.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@68598 91177308-0d34-0410-b5e6-96231b3b80d8
2009-04-08 05:41:03 +00:00
Chris Lattner
62ce3b31a7 fix rdar://6762290, a crash compiling cxx filt with clang.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@68500 91177308-0d34-0410-b5e6-96231b3b80d8
2009-04-07 05:03:34 +00:00
Evan Cheng
de62192843 Throttle back "fold select into operand" transformation. InstCombine should not generate selects of two constants unless they are selects of 0 and 1.
e.g.
define i32 @t1(i32 %c, i32 %x) nounwind {
       %t1 = icmp eq i32 %c, 0
       %t2 = lshr i32 %x, 18
       %t3 = select i1 %t1, i32 %t2, i32 %x
       ret i32 %t3
}

was turned into

define i32 @t2(i32 %c, i32 %x) nounwind {
       %t1 = icmp eq i32 %c, 0
       %t2 = select i1 %t1, i32 18, i32 0
       %t3 = lshr i32 %x, %t2
       ret i32 %t3
}

For most targets, that means materializing two constants and then a select. e.g. On x86-64

movl    %esi, %eax
shrl    $18, %eax
testl   %edi, %edi
cmovne  %esi, %eax
ret

=>

xorl    %eax, %eax
testl   %edi, %edi
movl    $18, %ecx
cmovne  %eax, %ecx
movl    %esi, %eax
shrl    %cl, %eax
ret

Also, the optimizer and codegen can reason about shl / and / add, etc. by a constant. This optimization will hinder optimizations using ComputeMaskedBits.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@68142 91177308-0d34-0410-b5e6-96231b3b80d8
2009-03-31 20:42:45 +00:00
Chris Lattner
e8e4921967 Fix PR3874 by restoring a condition I removed, but making it more
precise than it used to be.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@67662 91177308-0d34-0410-b5e6-96231b3b80d8
2009-03-25 00:28:58 +00:00
Chris Lattner
a0e6969bbe canonicalize inttoptr and ptrtoint instructions which cast pointers
to/from integer types that are not intptr_t to convert to intptr_t
then do an integer conversion to the dest type.  This exposes the
cast to the optimizer.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@67638 91177308-0d34-0410-b5e6-96231b3b80d8
2009-03-24 18:35:40 +00:00
Chris Lattner
4f9797d683 two changes:
1. Make instcombine always canonicalize trunc x to i1 into an icmp(x&1).  This 
   exposes the AND to other instcombine xforms and is more of what the code
   generator expects.
2. Rewrite the remaining trunc pattern match to use 'match', which 
   simplifies it a lot.
   


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@67635 91177308-0d34-0410-b5e6-96231b3b80d8
2009-03-24 18:15:30 +00:00
Chris Lattner
344c7c5cc4 Fix instcombine to not introduce undefined shifts when merging two
shifts together.  This fixes PR3851.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@67411 91177308-0d34-0410-b5e6-96231b3b80d8
2009-03-20 22:41:15 +00:00
Chris Lattner
b44b3666f9 Fix PR3826 - InstComb assert with vector shift, by not calling ComputeNumSignBits on a vector.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@67211 91177308-0d34-0410-b5e6-96231b3b80d8
2009-03-18 16:32:19 +00:00
Duncan Sands
5b7cfb02f7 Fix PR3694: add an instcombine micro-optimization that helps
clean up when using variable length arrays in llvm-gcc.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@65832 91177308-0d34-0410-b5e6-96231b3b80d8
2009-03-02 09:18:21 +00:00
Chris Lattner
58b1ac76d4 Fix PR3667
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@65464 91177308-0d34-0410-b5e6-96231b3b80d8
2009-02-25 18:20:01 +00:00
Dan Gohman
85937de26b Add a testcase for the problem fixed in r65289.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@65365 91177308-0d34-0410-b5e6-96231b3b80d8
2009-02-24 02:17:42 +00:00
Dan Gohman
0001e56f15 Fix a ValueTracking rule: RHS means operand 1, not 0. Add a simple
ashr instcombine to help expose this code. And apply the fix to
SelectionDAG's copy of this code too.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@65364 91177308-0d34-0410-b5e6-96231b3b80d8
2009-02-24 02:00:40 +00:00
Nick Lewycky
2ec0dbf961 Don't sign extend the char when expanding char -> int during
load(bitcast(char[4] to i32*)) evaluation.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@65246 91177308-0d34-0410-b5e6-96231b3b80d8
2009-02-21 20:50:42 +00:00
Chris Lattner
36d3e326df rename a function to indicate that it checks for profitability as well
as legality.  Make load sinking and gep sinking more careful: we only
do it when it won't pessimize loads from the stack.  This has the added
benefit of not producing code that is unanalyzable to SROA.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@65209 91177308-0d34-0410-b5e6-96231b3b80d8
2009-02-21 00:46:50 +00:00
Dan Gohman
38ad0191e9 Change the argument type in this test to something less convoluted,
since it isn't actually used. 


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@64883 91177308-0d34-0410-b5e6-96231b3b80d8
2009-02-18 04:25:04 +00:00
Chris Lattner
a84f47c3e7 commit a tweaked version of Daniel's patch for PR3599. We now
eliminate all the extensions and all but the one required truncate
from the testcase, but the or/and/shift stuff still isn't zapped.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@64809 91177308-0d34-0410-b5e6-96231b3b80d8
2009-02-17 20:47:23 +00:00
Dan Gohman
ecd0fb51cb Fix EnforceKnownAlignment so that it doesn't ever reduce the alignment
of an alloca or global variable.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@64693 91177308-0d34-0410-b5e6-96231b3b80d8
2009-02-16 23:02:21 +00:00
Dan Gohman
926b0a27b9 Change these tests to use regular loads instead of llvm.x86.sse2.loadu.dq.
Enhance instcombine to use the preferred field of
GetOrEnforceKnownAlignment in more cases, so that regular IR operations are
optimized in the same way that the intrinsics currently are.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@64623 91177308-0d34-0410-b5e6-96231b3b80d8
2009-02-16 00:44:23 +00:00
Nate Begeman
0f123cf732 Add suppport for ConstantExprs of shufflevectors whose result type is not equal to the
type of the vectors being shuffled.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@64401 91177308-0d34-0410-b5e6-96231b3b80d8
2009-02-12 21:28:33 +00:00
Mon P Wang
6753f959d2 Instrcombine should not change load(cast p) to cast(load p) if the cast
changes the address space of the pointer.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@64035 91177308-0d34-0410-b5e6-96231b3b80d8
2009-02-07 22:19:29 +00:00
Duncan Sands
09750273a4 Allow the inverse transform x86_fp80 -> i80 (also
fires during the Ada build).


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@63731 91177308-0d34-0410-b5e6-96231b3b80d8
2009-02-04 11:17:06 +00:00
Duncan Sands
a06aef6ec5 Fix PR3468: a crash when constant folding a bitcast of
i80 to x86 long double (this was presumably generated
by sroa).


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@63730 91177308-0d34-0410-b5e6-96231b3b80d8
2009-02-04 10:17:14 +00:00
Evan Cheng
388df627cc APInt'fy SimplifyDemandedVectorElts so it can analyze vectors with more than 64 elements.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@63631 91177308-0d34-0410-b5e6-96231b3b80d8
2009-02-03 10:05:09 +00:00
Chris Lattner
d42bd99696 reduce testcase.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@63499 91177308-0d34-0410-b5e6-96231b3b80d8
2009-02-02 06:55:45 +00:00
Nick Lewycky
4333f49afe Reinstate this optimization to fold icmp of xor when possible. Don't try to
turn icmp eq a+x, b+x into icmp eq a, b if a+x or b+x has other uses. This
may have been increasing register pressure leading to the bzip2 slowdown.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@63487 91177308-0d34-0410-b5e6-96231b3b80d8
2009-01-31 21:30:05 +00:00
Chris Lattner
39c27eddc5 Fix PR3452 (an infinite loop bootstrapping) by disabling the recent
improvements to the EvaluateInDifferentType code.  This code works 
by just inserted a bunch of new code and then seeing if it is 
useful.  Instcombine is not allowed to do this: it can only insert
new code if it is useful, and only when it is converging to a more
canonical fixed point.  Now that we iterate when DCE makes progress,
this causes an infinite loop when the code ends up not being used.




git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@63483 91177308-0d34-0410-b5e6-96231b3b80d8
2009-01-31 19:05:27 +00:00
Chris Lattner
d1b5e3fad9 now that all the pieces are in place, teach instcombine's
simplifydemandedbits to simplify instructions with *multiple
uses* in contexts where it can get away with it.  This allows
it to simplify the code in multi-use-or.ll into a single 'add 
double'.

This change is particularly interesting because it will cover
up for some common codegen bugs with large integers created due
to the recent SROA patch.  When working on fixing those bugs,
this should be disabled.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@63481 91177308-0d34-0410-b5e6-96231b3b80d8
2009-01-31 08:40:03 +00:00
Chris Lattner
1e19d603e0 make sure to set Changed=true when instcombine hacks on the code,
not doing so prevents it from properly iterating and prevents it
from deleting the entire body of dce-iterate.ll


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@63476 91177308-0d34-0410-b5e6-96231b3b80d8
2009-01-31 07:04:22 +00:00
Mon P Wang
fe6d2cd9d1 Fixed optimization of combining two shuffles where the first shuffle inputs
has a different number of elements than the output.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@62998 91177308-0d34-0410-b5e6-96231b3b80d8
2009-01-26 04:39:00 +00:00
Torok Edwin
08ffee539e testcase for PR3381.
Also it was an empty struct, not a void after all.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@62920 91177308-0d34-0410-b5e6-96231b3b80d8
2009-01-24 17:16:04 +00:00
Chris Lattner
3914f721cc Make InstCombineStoreToCast handle aggregates more aggressively,
handling the case in Transforms/InstCombine/cast-store-gep.ll, which
is a heavily reduced testcase from Clang on x86-64.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@62904 91177308-0d34-0410-b5e6-96231b3b80d8
2009-01-24 01:00:13 +00:00
Dale Johannesen
541ed9fd02 Do not use host floating point types when emitting
ASCII IR; loading and storing these can change the
bits of NaNs on some hosts.  Remove or add warnings
at a few other places using host floating point;
this is a bad thing to do in general.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@62712 91177308-0d34-0410-b5e6-96231b3b80d8
2009-01-21 20:32:55 +00:00
Dale Johannesen
677eae3d96 Disable on x86_64 until I figure out what's wrong.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@62660 91177308-0d34-0410-b5e6-96231b3b80d8
2009-01-21 02:08:30 +00:00
Dale Johannesen
ed6af24e14 Make special cases (0 inf nan) work for frem.
Besides APFloat, this involved removing code
from two places that thought they knew the
result of frem(0., x) but were wrong.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@62645 91177308-0d34-0410-b5e6-96231b3b80d8
2009-01-21 00:35:19 +00:00
Dale Johannesen
67e1e7c3d8 Calls to fmod, it turns out, are constant-folded by
invoking the host fmod, not by lowering to frem and
constant-folding that.  Fix this so it tests what I
want to test.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@62622 91177308-0d34-0410-b5e6-96231b3b80d8
2009-01-20 21:58:13 +00:00
Dale Johannesen
549170206e Move & restructure test per review.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@62538 91177308-0d34-0410-b5e6-96231b3b80d8
2009-01-19 22:33:12 +00:00
Chris Lattner
71759c491c Fix PR3335 by not turning a store to one address space into a store to another.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@62351 91177308-0d34-0410-b5e6-96231b3b80d8
2009-01-16 20:12:52 +00:00
Evan Cheng
4e56ab2cf4 Clean up previous cast optimization a bit. Also make zext elimination a bit more aggressive: if it's not necessary to emit an AND (i.e. high bits are already zero), it's profitable to evaluate the operand at a different type.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@62297 91177308-0d34-0410-b5e6-96231b3b80d8
2009-01-16 02:11:43 +00:00
Evan Cheng
f35fd547ac - Teach CanEvaluateInDifferentType of this xform: sext (zext ty1), ty2 -> zext ty2
- Looking at the number of sign bits of the a sext instruction to determine  whether new trunc + sext pair should be added when its source is being evaluated in a different type.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@62263 91177308-0d34-0410-b5e6-96231b3b80d8
2009-01-15 17:01:23 +00:00
Dan Gohman
6893cd7615 Make instcombine ensure that all allocas are explicitly aligned at at
least their preferred alignment.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@62176 91177308-0d34-0410-b5e6-96231b3b80d8
2009-01-13 20:18:38 +00:00
Chris Lattner
a80d668215 Implement rdar://6480391, extending of equality icmp's to avoid a truncation.
I noticed this in the code compiled for a routine using std::map, which produced
this code:
	%25 = tail call i32 @memcmp(i8* %24, i8* %23, i32 6) nounwind readonly
	%.lobit.i = lshr i32 %25, 31		; <i32> [#uses=1]
	%tmp.i = trunc i32 %.lobit.i to i8		; <i8> [#uses=1]
	%toBool = icmp eq i8 %tmp.i, 0		; <i1> [#uses=1]
	br i1 %toBool, label %bb3, label %bb4
which compiled to:

	call	L_memcmp$stub
	shrl	$31, %eax
	testb	%al, %al
	jne	LBB1_11	## 

with this change, we compile it to:

	call	L_memcmp$stub
	testl	%eax, %eax
	js	LBB1_11

This triggers all the time in common code, with patters like this:

	%169 = and i32 %ply, 1		; <i32> [#uses=1]
	%170 = trunc i32 %169 to i8		; <i8> [#uses=1]
	%toBool = icmp ne i8 %170, 0		; <i1> [#uses=1]

 	%7 = lshr i32 %6, 24		; <i32> [#uses=1]
	%9 = trunc i32 %7 to i8		; <i8> [#uses=1]
	%10 = icmp ne i8 %9, 0		; <i1> [#uses=1]

etc



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@61985 91177308-0d34-0410-b5e6-96231b3b80d8
2009-01-09 07:47:06 +00:00
Chris Lattner
46cd5a13e5 Fix part 3/2 of PR3290, making instcombine zap (gep(bitcast)) when possible.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@61980 91177308-0d34-0410-b5e6-96231b3b80d8
2009-01-09 05:44:56 +00:00
Chris Lattner
0f2831c820 ValueTracker can't assume that an alloca with no specified alignment
will get its preferred alignment.  It has to be careful and cautiously assume
it will just get the ABI alignment.  This prevents instcombine from rounding
up the alignment of a load/store without adjusting the alignment of the alloca.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@61934 91177308-0d34-0410-b5e6-96231b3b80d8
2009-01-08 19:28:38 +00:00
Chris Lattner
06ebbcc71d make m_ConstantInt(int64_t) safely match ConstantInt's that are larger than i64.
This fixes an instcombine crash on PR3235.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@61775 91177308-0d34-0410-b5e6-96231b3b80d8
2009-01-05 23:45:50 +00:00
Bill Wendling
a96658c417 XFAIL this test. The xform was removed.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@61624 91177308-0d34-0410-b5e6-96231b3b80d8
2009-01-04 06:32:28 +00:00
Bill Wendling
3479be91c4 Add transformation:
xor (or (icmp, icmp), true) -> and(icmp, icmp)

This is possible because of De Morgan's law.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@61537 91177308-0d34-0410-b5e6-96231b3b80d8
2009-01-01 01:18:23 +00:00
Nick Lewycky
2a8f6597a3 Make all the vector elements positive in an srem of constant vector.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@61195 91177308-0d34-0410-b5e6-96231b3b80d8
2008-12-18 06:31:11 +00:00
Bill Wendling
03aae5f7e1 Use m_Specific() instead of double matching.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60341 91177308-0d34-0410-b5e6-96231b3b80d8
2008-12-01 08:09:47 +00:00
Chris Lattner
d8aafcb200 simplify these patterns using m_Specific. No need to grep for
xor in testcase (or is a substring).


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60328 91177308-0d34-0410-b5e6-96231b3b80d8
2008-12-01 05:16:26 +00:00
Chris Lattner
05f18920e1 Teach inst combine to merge GEPs through PHIs. This is really
important because it is sinking the loads using the GEPs, but
not the GEPs themselves.  This triggers 647 times on 403.gcc
and makes the .s file much much nicer.  For example before:

        je      LBB1_87 ## bb78
LBB1_62:        ## bb77
        leal    84(%esi), %eax
LBB1_63:        ## bb79
        movl    (%eax), %eax
...
LBB1_87:        ## bb78
        movl    $0, 4(%esp)
        movl    %esi, (%esp)
        call    L_make_decl_rtl$stub
        jmp     LBB1_62 ## bb77


after:

        jne     LBB1_63 ## bb79
LBB1_62:        ## bb78
        movl    $0, 4(%esp)
        movl    %esi, (%esp)
        call    L_make_decl_rtl$stub
LBB1_63:        ## bb79
        movl    84(%esi), %eax

The input code was (and the GEPs are merged and
the PHI is now eliminated by instcombine):

        br i1 %tmp233, label %bb78, label %bb77
bb77:           
        %tmp234 = getelementptr %struct.tree_node* %t_addr.3, i32 0, i32 0, i32 22              
        br label %bb79
bb78:           
        call void @make_decl_rtl(%struct.tree_node* %t_addr.3, i8* null) nounwind
        %tmp235 = getelementptr %struct.tree_node* %t_addr.3, i32 0, i32 0, i32 22              
        br label %bb79
bb79:           
        %iftmp.12.0.in = phi %struct.rtx_def** [ %tmp235, %bb78 ], [ %tmp234, %bb77 ]           
        %iftmp.12.0 = load %struct.rtx_def** %iftmp.12.0.in             



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60322 91177308-0d34-0410-b5e6-96231b3b80d8
2008-12-01 02:34:36 +00:00
Bill Wendling
b3833d1eb9 Implement ((A|B)&1)|(B&-2) -> (A&1) | B transformation. This also takes care of
permutations of this pattern.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60312 91177308-0d34-0410-b5e6-96231b3b80d8
2008-12-01 01:07:11 +00:00
Bill Wendling
b01865c210 Add instruction combining for ((A&~B)|(~A&B)) -> A^B and all permutations.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60291 91177308-0d34-0410-b5e6-96231b3b80d8
2008-11-30 13:52:49 +00:00
Bill Wendling
7f0ef6b325 Implement (A&((~A)|B)) -> A&B transformation in the instruction combiner. This
takes care of all permutations of this pattern.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60290 91177308-0d34-0410-b5e6-96231b3b80d8
2008-11-30 13:08:13 +00:00
Bill Wendling
6e1783fb4a getSExtValue() doesn't work for ConstantInts with bitwidth > 64 bits. Use all
APInt calls instead.

This fixes PR3144.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60288 91177308-0d34-0410-b5e6-96231b3b80d8
2008-11-30 12:38:24 +00:00
Bill Wendling
13441c57ec Strengthen check for div inst-combining.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60276 91177308-0d34-0410-b5e6-96231b3b80d8
2008-11-30 04:33:53 +00:00
Bill Wendling
e1196d6d3e Instcombine was illegally transforming -X/C into X/-C when either X or C
overflowed on negation. This commit checks to make sure that neithe C nor X
overflows. This requires that the RHS of X (a subtract instruction) be a
constant integer.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60275 91177308-0d34-0410-b5e6-96231b3b80d8
2008-11-30 03:42:12 +00:00
Nick Lewycky
8ca5248522 Chris prefers icmp/select over udiv!
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60187 91177308-0d34-0410-b5e6-96231b3b80d8
2008-11-27 22:41:10 +00:00
Nick Lewycky
895f085385 Add a couple of missed optimizations on integer vectors. Multiply and divide
by 1, as well as multiply by -1.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60182 91177308-0d34-0410-b5e6-96231b3b80d8
2008-11-27 20:21:08 +00:00
Nick Lewycky
0c73079855 Optimize (x/y)*y into x-(x%y) in general. Div and rem are about the same, and
a subtract is cheaper than a multiply. This generalizes an existing transform.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@59800 91177308-0d34-0410-b5e6-96231b3b80d8
2008-11-21 07:33:58 +00:00
Chris Lattner
a74cefa6d3 Handle the case where there is no "not". It is possible it got
folded into the select.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@59389 91177308-0d34-0410-b5e6-96231b3b80d8
2008-11-16 04:25:26 +00:00
Chris Lattner
6093b36f47 make this actually test what it is trying to.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@59386 91177308-0d34-0410-b5e6-96231b3b80d8
2008-11-16 04:21:51 +00:00
Bill Wendling
c143bcf9ac If the LHS of the FCMP is coming from a UIToFP instruction, then we don't want
to generate signed ICMP instructions to replace the FCMP. This would violate
the following:

define i1 @test1(i32 %val) {
  %1 = uitofp i32 %val to double
  %2 = fcmp ole double %1, 0.000000e+00
  ret i1 %2
}

would be transformed into:

define i1 @test1(i32 %val) {
  %1 = icmp slt i33 %val, 1
  ret i1 %1
}

which is obviously wrong. This patch modifes InstCombiner::FoldFCmp_IntToFP_Cst
to handle when the LHS comes from UIToFP.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@58929 91177308-0d34-0410-b5e6-96231b3b80d8
2008-11-09 04:26:50 +00:00
Nick Lewycky
8e39432ea9 Fix demanded bits analysis with srem by negative number. Based on a patch
by Richard Osborne.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@58555 91177308-0d34-0410-b5e6-96231b3b80d8
2008-11-02 02:41:50 +00:00
Dan Gohman
21440acc06 Fix this recently moved code to use the correct type. CI is now a
ConstantInt, and SI is the original cast instruction. This fixes
PR2996.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@58549 91177308-0d34-0410-b5e6-96231b3b80d8
2008-11-02 00:17:33 +00:00
Dan Gohman
1975d03183 Canonicalize sext(i1) to i1?-1:0, and update various instcombine
optimizations accordingly.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@58457 91177308-0d34-0410-b5e6-96231b3b80d8
2008-10-30 20:40:10 +00:00
Dan Gohman
b493b2774c (A & sext(C)) | (B & ~sext(C) -> C ? A : B
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@58351 91177308-0d34-0410-b5e6-96231b3b80d8
2008-10-28 22:38:57 +00:00
Nick Lewycky
04aa2c3520 Don't try to create a mask when we don't need one. Fixes a crash.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@58075 91177308-0d34-0410-b5e6-96231b3b80d8
2008-10-24 06:14:27 +00:00
Dan Gohman
2276a7bc8e Teach instcombine's visitLoad to scan back several instructions
to find opportunities for store-to-load forwarding or load CSE,
in the same way that visitStore scans back to do DSE. Also, define
a new helper function for testing whether the addresses of two
memory accesses are known to have the same value, and use it in
both visitStore and visitLoad.

These two changes allow instcombine to eliminate loads in code
produced by front-ends that frequently emit obviously redundant
addressing for memory references.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@57608 91177308-0d34-0410-b5e6-96231b3b80d8
2008-10-15 23:19:35 +00:00
Evan Cheng
403006205f Combine (fcmp cc0 x, y) | (fcmp cc1 x, y) into a single fcmp when possible.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@57515 91177308-0d34-0410-b5e6-96231b3b80d8
2008-10-14 18:44:08 +00:00
Evan Cheng
4990b257dd - Somehow I forgot about one / une.
- Renumber fcmp predicates to match their icmp counterparts.
- Try swapping operands to expose more optimization opportunities.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@57513 91177308-0d34-0410-b5e6-96231b3b80d8
2008-10-14 18:13:38 +00:00
Evan Cheng
8db90725cb Optimize anding of two fcmp into a single fcmp if the operands are the same. e.g. uno && ueq -> ueq
ord && olt -> olt
     ord && ueq -> oeq


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@57507 91177308-0d34-0410-b5e6-96231b3b80d8
2008-10-14 17:15:11 +00:00
Chris Lattner
a6321b40c2 Fix PR2697 by rewriting the '(X / pos) op neg' logic. This also changes
a couple other cases for clarity, but shouldn't affect correctness.

Patch by Eli Friedman!



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@57387 91177308-0d34-0410-b5e6-96231b3b80d8
2008-10-11 22:55:00 +00:00
Chris Lattner
8c34cd287a rewrite bswap matching to be more general, allowing arbitrary
shifting and masking inside a bswap expr.  This allows it to handle
the cases from PR2842, which involve the intermediate 'or' 
expressions being shifted, not just the input value.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@57095 91177308-0d34-0410-b5e6-96231b3b80d8
2008-10-05 02:13:19 +00:00
Nick Lewycky
a06cf82a7b Fix misoptimization of: xor i1 (icmp eq (X, C1), icmp s[lg]t (X, C2))
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@56834 91177308-0d34-0410-b5e6-96231b3b80d8
2008-09-30 06:08:34 +00:00
Dan Gohman
81b28ceab6 Improve instcombine's handling of integer min and max in two ways:
- Recognize expressions like "x > -1 ? x : 0" as min/max and turn them
   into expressions like "x < 0 ? 0 : x", which is easily recognizable
   as a min/max operation.
 - Refrain from folding expression like "y/2 < 1" to "y < 2" when the
   comparison is being used as part of a min or max idiom, like
   "y/2 < 1 ? 1 : y/2". In that case, the division has another use, so
   folding doesn't eliminate it, and obfuscates the min/max, making it
   harder to recognize as a min/max operation.

These benefit ScalarEvolution, CodeGen, and anything else that wants to
recognize integer min and max.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@56246 91177308-0d34-0410-b5e6-96231b3b80d8
2008-09-16 18:46:06 +00:00
Dan Gohman
4f833d4351 On 64-bit targets, change 32-bit getelementptr indices to be 64-bit
getelementptr indices, inserting an explicit cast if necessary.
This helps expose the sign-extension operation to other optimizations.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@56133 91177308-0d34-0410-b5e6-96231b3b80d8
2008-09-11 23:06:38 +00:00
Dan Gohman
3139ff8f7b Fix a vectorshuffle instcombine bug introduced by r55995.
Patch by Nicolas Capens!


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@56129 91177308-0d34-0410-b5e6-96231b3b80d8
2008-09-11 22:47:57 +00:00
Dan Gohman
1df3fd6683 Fix an icmp+sdiv optimization to check for and handle an overflow
condition. This fixes PR2740.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@56076 91177308-0d34-0410-b5e6-96231b3b80d8
2008-09-10 23:30:57 +00:00
Dan Gohman
488fbfc69e Make SimplifyDemandedVectorElts simplify vectors with multiple
users, and teach it about shufflevector instructions.

Also, fix a subtle bug in SimplifyDemandedVectorElts'
insertelement code.

This is a patch that was originally written by Eli Friedman,
with some fixes and cleanup by me.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@55995 91177308-0d34-0410-b5e6-96231b3b80d8
2008-09-09 18:11:14 +00:00
Nick Lewycky
83c05e5d30 Don't crash when trying to constant fold a vector with some elements that can't
be folded. Instead, fail to fold the entire vector.

We could also return a vector with some elements folded and some not. If anyone
thinks that's a better approach, please speak up!


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@55689 91177308-0d34-0410-b5e6-96231b3b80d8
2008-09-03 05:54:33 +00:00
Nick Lewycky
5d52c4501a Revert r54876 r54877 r54906 and r54907. Evan found that these caused a 20%
slowdown in bzip2.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@55113 91177308-0d34-0410-b5e6-96231b3b80d8
2008-08-21 05:56:10 +00:00
Nick Lewycky
91a0f78265 Consider the case where xor by -1 and xor by 128 have been combined already to
produce an xor by 127.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@54906 91177308-0d34-0410-b5e6-96231b3b80d8
2008-08-17 19:58:24 +00:00
Nick Lewycky
1b344bc986 Xor'ing both sides of icmp by sign-bit is equivalent to swapping signedness of
the predicate.

Also, make this optz'n apply in more cases where it's safe to do so.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@54876 91177308-0d34-0410-b5e6-96231b3b80d8
2008-08-17 07:34:14 +00:00
Owen Anderson
7c856c09cd Remove GCSE and LoadVN from the testsuite.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@54832 91177308-0d34-0410-b5e6-96231b3b80d8
2008-08-16 00:00:54 +00:00
Dan Gohman
a60832b018 Fix a bogus srem rule - a negative value srem'd by a power-of-2
can have a non-negative result; for example, -16%16 is 0. Also,
clarify the related comments. This fixes PR2670.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@54767 91177308-0d34-0410-b5e6-96231b3b80d8
2008-08-13 23:12:35 +00:00
Chris Lattner
b8cd4d3d49 Implement support for simplifying vector comparisons by 0.0 and 1.0 like we
do for scalars.  Patch contributed by Nicolas Capens

This also generalizes the previous xforms to work on long double, now that 
isExactlyValue works for long double.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@54653 91177308-0d34-0410-b5e6-96231b3b80d8
2008-08-11 22:06:05 +00:00
Dan Gohman
4ce9627e97 Fix a shufflevector instcombine that was emitting invalid masks indices
when it meant to be emitting undef indices.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@54417 91177308-0d34-0410-b5e6-96231b3b80d8
2008-08-06 18:17:32 +00:00
Chris Lattner
46bbad217b optimize a common idiom generated by clang for bitfield access, PR2638.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@54408 91177308-0d34-0410-b5e6-96231b3b80d8
2008-08-06 07:35:52 +00:00
Chris Lattner
5af5f463e1 Zap sitofp/fptoui pairs. In all cases when the sign difference
matters, the result is undefined anyway.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@54396 91177308-0d34-0410-b5e6-96231b3b80d8
2008-08-06 05:13:06 +00:00
Nick Lewycky
b30591ec64 Reinstate this optimization, but without the miscompile. Thanks to Bill for
tracking down that this was breaking llvm-gcc bootstrap on Linux.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@54394 91177308-0d34-0410-b5e6-96231b3b80d8
2008-08-06 04:54:03 +00:00
Bill Wendling
5226698f67 Just grep for through the LL code instead of the ASM code
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@54389 91177308-0d34-0410-b5e6-96231b3b80d8
2008-08-06 00:10:32 +00:00