Commit Graph

757 Commits

Author SHA1 Message Date
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