Commit Graph

984 Commits

Author SHA1 Message Date
Chris Lattner
830f3f205d fix rdar://7590304, an infinite loop in instcombine. In the invoke
case, instcombine can't zap the invoke for fear of changing the CFG.
However, we have to do something to prevent the next iteration of
instcombine from inserting another store -> undef before the invoke
thereby getting into infinite iteration between dead store elim and
store insertion.

Just zap the callee to null, which will prevent the next iteration
from doing anything.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@94985 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-01 18:04:58 +00:00
Eli Friedman
b406c47ea9 Remove test which is no longer relevant.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@94944 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-31 04:40:45 +00:00
Eli Friedman
be7cfa6033 Simplify/generalize the xor+add->sign-extend instcombine.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@94943 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-31 04:29:12 +00:00
Eli Friedman
694488f477 Add a small transform: transform -(X<<Y) to (-X<<Y) when the shift has a single
use and X is free to negate.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@94941 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-31 02:30:23 +00:00
Bob Wilson
8ad1f0e284 Remove ARM-specific calling convention from this test. Target data is
needed for this test, but otherwise, there's nothing ARM-specific about
it and no need to specify the calling convention.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@94862 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-30 00:40:23 +00:00
Eric Christopher
36664bfc7a Revert my last couple of patches. They appear to have broken bison.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@94841 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-29 21:16:24 +00:00
Bob Wilson
3eb4f7e2dd Improve isSafeToLoadUnconditionally to recognize that GEPs with constant
indices are safe if the result is known to be within the bounds of the
underlying object.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@94829 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-29 19:19:08 +00:00
Eric Christopher
949124ce0f Add constant support to object size handling and remove default
lowering. We'll either figure it out, or not and be lowered by
SelectionDAGBuild.

Add test.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@94775 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-29 01:09:57 +00:00
Duncan Sands
2c47368a7d Fix PR6165. The bug was that LHSKnownZero was being and'd with DemandedMask
when it should have been and'd with LowBits.  Fix that and while there beef
up the logic in the case of a negative LHS.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@94745 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-28 17:22:42 +00:00
Chris Lattner
abb992d6a3 change the canonical form of "cond ? -1 : 0" to be
"sext cond" instead of a select.  This simplifies some instcombine
code, matches the policy for zext (cond ? 1 : 0 -> zext), and allows
us to generate better code for a testcase on ppc.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@94339 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-24 00:09:49 +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
Mon P Wang
e4a0a151a5 InstCombine should not fold sext/zext of a vector and a bitcast to a scalar to a sext/zext
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@94280 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-23 04:35:57 +00:00
Chris Lattner
c0404b3715 optimize ~(~X >>s Y) --> (X >>s Y), patch by Edmund Grimley
Evans!


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@93884 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-19 18:16:19 +00:00
Chris Lattner
cd5adbbc0c my instcombine transformations to make extension elimination more
aggressive changed the canonical form from sext(trunc(x)) to ashr(lshr(x)),
make sure to transform a couple more things into that canonical form,
and catch a case where we missed turning zext/shl/ashr into a single sext.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@93787 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-18 22:19:16 +00:00
Chris Lattner
1dafbe1738 filecheckize this.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@93776 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-18 22:00:46 +00:00
Chris Lattner
569a7b9237 remove a redundant test, filecheckize another.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@93774 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-18 21:55:43 +00:00
Bill Wendling
4eb66b8d0e Reduce fsub-fadd.ll and merge it into fsub-fsub.ll. Rename fsub-fsub.ll to
fsub.ll and FileCheckify it.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@93669 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-17 00:21:21 +00:00
Bill Wendling
22f3b9faac When the visitSub method was split into visitSub and visitFSub, this xform was
added to the FSub version. However, the original version of this xform guarded
against doing this for floating point (!Op0->getType()->isFPOrFPVector()).

This is causing LLVM to perform incorrect xforms for code like:

void func(double *rhi, double *rlo, double xh, double xl, double yh, double yl){
  double mh, ml;
  double c = 134217729.0;
  double up, u1, u2, vp, v1, v2;
        
  up = xh*c;
  u1 = (xh - up) + up;
  u2 = xh - u1;
        
  vp = yh*c;
  v1 = (yh - vp) + vp;
  v2 = yh - v1;
        
  mh = xh*yh;
  ml = (((u1*v1 - mh) + (u1*v2)) + (u2*v1)) + (u2*v2);
  ml += xh*yl + xl*yh;
        
  *rhi = mh + ml;
  *rlo = (mh - (*rhi)) + ml;
}

The last line was optimized away, but rl is intended to be the difference
between the infinitely precise result of mh + ml and after it has been rounded
to double precision.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@93369 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-13 23:23:17 +00:00
Chris Lattner
8c2143fce9 disable this testcase, PR5997
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@93206 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-11 23:18:33 +00:00
Chris Lattner
8e76764de8 add one more bitfield optimization, allowing clang to generate
good code on PR4216:

_test_bitfield:                                             ## @test_bitfield
	orl	$32962, %edi
	movl	$4294941946, %eax
	andq	%rdi, %rax
	ret

instead of:

_test_bitfield:
        movl    $4294941696, %ecx
        movl    %edi, %eax
        orl     $194, %edi
        orl     $32768, %eax
        andq    $250, %rdi
        andq    %rax, %rcx
        movq    %rdi, %rax
        orq     %rcx, %rax
        ret

Evan is looking into the remaining andq+imm -> andl optimization.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@93147 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-11 06:55:24 +00:00
Chris Lattner
7acc4b1281 Extend CanEvaluateZExtd to handle and/or/xor more aggressively in the
BitsToClear case.  This allows it to promote expressions which have an
and/or/xor after the lshr, promoting cases like test2 (from PR4216) 
and test3 (random extample extracted from a spec benchmark).

clang now compiles the code in PR4216 into:

_test_bitfield:                                             ## @test_bitfield
	movl	%edi, %eax
	orl	$194, %eax
	movl	$4294902010, %ecx
	andq	%rax, %rcx
	orl	$32768, %edi
	andq	$39936, %rdi
	movq	%rdi, %rax
	orq	%rcx, %rax
	ret

instead of:

_test_bitfield:                                             ## @test_bitfield
	movl	%edi, %eax
	orl	$194, %eax
	movl	$4294902010, %ecx
	andq	%rax, %rcx
	shrl	$8, %edi
	orl	$128, %edi
	shlq	$8, %rdi
	andq	$39936, %rdi
	movq	%rdi, %rax
	orq	%rcx, %rax
	ret

which is still not great, but is progress.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@93145 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-11 04:05:13 +00:00
Chris Lattner
789162a309 Remove the dead TD argument to CanEvaluateZExtd, and add a
new BitsToClear result which allows us to start promoting
expressions that end with a lshr-by-constant.  This is
conservatively correct and better than what we had before
(see testcases) but still needs to be extended further.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@93144 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-11 03:32:00 +00:00
Chris Lattner
11ea812424 teach sext optimization to handle truncs from types that are not
the dest of the sext.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@93128 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-10 20:30:41 +00:00
Chris Lattner
9ee947c224 teach zext optimization how to deal with truncs that don't come from
the zext dest type.  This allows us to handle test52/53 in cast.ll,
and allows llvm-gcc to generate much better code for PR4216 in -m64
mode:

_test_bitfield:                                             ## @test_bitfield
	orl	$32962, %edi
	movl	%edi, %eax
	andl	$-25350, %eax
	ret

This also fixes a bug handling vector extends, ensuring that the
mask produced is a vector constant, not an integer constant.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@93127 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-10 20:25:54 +00:00
Chris Lattner
dde5ee5d37 now that the cost model has changed, we can always consider
elimination of a sign extend to be a win, which simplifies 
the client of CanEvaluateSExtd, and allows us to eliminate
more casts (examples taken from real code).


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@93109 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-10 07:40:50 +00:00
Chris Lattner
f4fb91181c change the preferred canonical form for a sign extension to be
lshr+ashr instead of trunc+sext.  We want to avoid type 
conversions whenever possible, it is easier to codegen expressions
without truncates and extensions.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@93107 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-10 07:08:30 +00:00
Chris Lattner
5324d80283 two changes:
1) don't try to optimize a sext or zext that is only used by a trunc, let
   the trunc get optimized first.  This avoids some pointless effort in
   some common cases since instcombine scans down a block in the first pass.
2) Change the cost model for zext elimination to consider an 'and' cheaper
   than a zext.  This allows us to do it more aggressively, and for the next
   patch to simplify the code quite a bit.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@93097 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-10 02:39:31 +00:00
Chris Lattner
d26c9e183e enhance CanEvaluateZExtd to handle shift left and sext, allowing
more expressions to be promoted and casts eliminated.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@93096 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-10 02:22:12 +00:00
Chris Lattner
a85732fa3b teach instcombine to delete sign extending shift pairs (sra(shl X, C), C) when
the input is already sign extended.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@93019 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-08 19:04:21 +00:00
Chris Lattner
8d10f9d4a8 teach ComputeNumSignBits to look through PHI nodes.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@92964 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-07 23:44:37 +00:00
Chris Lattner
e3874deb61 filecheckize
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@92963 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-07 23:42:23 +00:00
Chris Lattner
075f692939 Enhance instcombine to reason more strongly about promoting computation
that feeds into a zext, similar to the patch I did yesterday for sext.
There is a lot of room for extension beyond this patch.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@92962 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-07 23:41:00 +00:00
Chris Lattner
e0e4cc7fd5 Teach instcombine's sext elimination logic to be more aggressive.
Previously, instcombine would only promote an expression tree to
the larger type if doing so eliminated two casts.  This is because
a need to manually do the sign extend after the promoted expression
tree with two shifts.  Now, we keep track of whether the result of
the computation is going to be properly sign extended already.  If
so, we can unconditionally promote the expression, which allows us
to zap more sext's.

This implements rdar://6598839 (aka gcc pr38751)


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@92815 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-06 01:56:21 +00:00
Chris Lattner
7a34d6c450 more rearrangement and cleanup, fix my test failure.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@92792 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-05 22:21:18 +00:00
Chris Lattner
c0f79af143 remove two trunc xforms that are subsumed by EvaluateInDifferentType.
The only difference is that EvaluateInDifferentType checks to ensure
they are profitable before doing them :)


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@92788 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-05 22:01:41 +00:00
Chris Lattner
c04d3d37e4 merge some tests.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@92786 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-05 21:54:09 +00:00
Chris Lattner
50ca0204c5 merge cast2 into cast.ll
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@92784 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-05 21:48:13 +00:00
Chris Lattner
6ae68a28b9 remove useless test.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@92782 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-05 21:46:22 +00:00
Chris Lattner
8e66905ce8 another example.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@92781 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-05 21:43:08 +00:00
Chris Lattner
022bd99d10 remove a useless negative test, add a rdar # to an xfail that I'm working on.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@92777 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-05 21:37:44 +00:00
Chris Lattner
a8f3ebbf5c clean up tests.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@92776 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-05 21:32:59 +00:00
Chris Lattner
464dc81803 just remove this xform which is subsumed by others.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@92775 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-05 21:16:30 +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
Dan Gohman
aceba31b7a Delete useless trailing semicolons.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@92740 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-05 17:55:26 +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
d7f5a58890 Truncate GEP indexes larger than the pointer size down to pointer size
when doing this transform if the GEP is not inbounds.  No testcase because
it is very difficult to trigger this: instcombine already canonicalizes
GEP indices to pointer size, so it relies specific permutations of the
instcombine worklist.

Thanks to Duncan for pointing this possible problem out.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@92495 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-04 18:57:15 +00:00
Chris Lattner
e4412c1f0b implement an instcombine xform needed by clang's codegen
on the example in PR4216.  This doesn't trigger in the testsuite,
so I'd really appreciate someone scrutinizing the logic for
correctness.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@92458 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-04 06:03:59 +00:00
Chris Lattner
56ba7a74b9 generalize the previous transformation to handle indexing into
arrays of structs and other arrays, so long as all the subsequent
indexes are constants.  This triggers frequently for stuff like:

@divisions = internal constant [29 x [2 x i32]] [[2 x i32] zeroinitializer, [2 x i32] [i32 0, i32 1], [2 x i32] [i32 0, i32 2], [2 x i32] [i32 0, i32 1], [2 x i32] zeroinitializer, [2 x i32] [i32 0, i32 1], [2 x i32] [i32 0, i32 1], [2 x i32] [i32 0, i32 2], [2 x i32] [i32 0, i32 2], [2 x i32] zeroinitializer, [2 x i32] zeroinitializer, [2 x i32] zeroinitializer, [2 x i32] [i32 0, i32 2], [2 x i32] [i32 0, i32 1], [2 x i32] zeroinitializer, [2 x i32] [i32 1, i32 0], [2 x i32] [i32 1, i32 1], [2 x i32] [i32 1, i32 1], [2 x i32] [i32 1, i32 2], [2 x i32] [i32 1, i32 1], [2 x i32] [i32 1, i32 0], [2 x i32] [i32 1, i32 2], [2 x i32] [i32 1, i32 2], [2 x i32] [i32 1, i32 0], [2 x i32] [i32 1, i32 0], [2 x i32] [i32 1, i32 0], [2 x i32] [i32 1, i32 1], [2 x i32] [i32 1, i32 2], [2 x i32] [i32 1, i32 2]], align 32 ; <[29 x [2 x i32]]*> [#uses=50]

	  %623 = getelementptr inbounds [29 x [2 x i32]]* @divisions, i64 0, i64 %619, i64 0 ; <i32*> [#uses=1]
	   %684 = icmp eq i32 %683, 999 

also for the "my_defs" table in 'gs', etc.




git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@92444 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-03 03:03:27 +00:00
Chris Lattner
df3d63b896 teach instcombine to optimize idioms like A[i]&42 == 0. This
occurs in 403.gcc in mode_mask_array, in safe-ctype.c (which
is copied in multiple apps) in _sch_istable, etc.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@92427 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-02 22:08:28 +00:00
Chris Lattner
b4f82b4b4f Teach the table lookup optimization to generate range compares
when a consequtive sequence of elements all satisfies the 
predicate.  Like the double compare case, this generates better
code than the magic constant case and generalizes to more than
32/64 element array lookups.

Here are some examples where it triggers.  From 403.gcc, most
accesses to the rtx_class array are handled, e.g.:

@rtx_class = constant [153 x i8] c"xxxxxmmmmmmmmxxxxxxxxxxxxmxxxxxxiiixxxxxxxxxxxxxxxxxxxooxooooooxxoooooox3x2c21c2222ccc122222ccccaaaaaa<<<<<<<<<<<<<<<<<<111111111111bbooxxxxxxxxxxcc2211x", align 32 ; <[153 x i8]*> [#uses=547]
   %142 = icmp eq i8 %141, 105
@rtx_class = constant [153 x i8] c"xxxxxmmmmmmmmxxxxxxxxxxxxmxxxxxxiiixxxxxxxxxxxxxxxxxxxooxooooooxxoooooox3x2c21c2222ccc122222ccccaaaaaa<<<<<<<<<<<<<<<<<<111111111111bbooxxxxxxxxxxcc2211x", align 32 ; <[153 x i8]*> [#uses=543]
	   %165 = icmp eq i8 %164, 60      

Also, most of the 59-element arrays (mode_class/rid_to_yy, etc) 
optimized before are actually range compares.  This lets 32-bit
machines optimize them.

400.perlbmk has stuff like this:

400.perlbmk: PL_regkind, even for 32-bit:
@PL_regkind = constant [62 x i8] c"\00\00\02\02\02\06\06\06\06\09\09\0B\0B\0D\0E\0E\0E\11\12\12\14\14\16\16\18\18\1A\1A\1C\1C\1E\1F !!!$$&'((((,-.///88886789:;8$", align 32 ; <[62 x i8]*> [#uses=4]
	   %811 = icmp ne i8 %810, 33 

@PL_utf8skip = constant [256 x i8] c"\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\01\02\02\02\02\02\02\02\02\02\02\02\02\02\02\02\02\02\02\02\02\02\02\02\02\02\02\02\02\02\02\02\02\03\03\03\03\03\03\03\03\03\03\03\03\03\03\03\03\04\04\04\04\04\04\04\04\05\05\05\05\06\06\07\0D", align 32 ; <[256 x i8]*> [#uses=94]
	   %12 = icmp ult i8 %10, 2
           
etc.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@92426 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-02 21:50:18 +00:00