Commit Graph

672 Commits

Author SHA1 Message Date
e538db4fb0 fix PR6193, only considering sign extensions *from i1* for this
xform.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@95642 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-09 01:12:41 +00:00
8609fda0f7 fix some problems handling large vectors reported in PR6230
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@95616 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-08 23:56:03 +00:00
74529826a7 fix logical-select to invoke filecheck right, and fix hte instcombine
xform it is checking to actually pass.  There is no need to match
m_SelectCst<0, -1> since instcombine canonicalizes that into not(sext).

Add matches for sext(not(x)) in addition to not(sext(x)).



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@95420 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-05 19:53:02 +00:00
724bea90b0 Remove this code for now. I have a better idea and will rewrite with
that in mind.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@95402 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-05 19:04:06 +00:00
e7b97471f8 Temporarily revert this since it appears to have caused a build
failure.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@95294 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-04 06:41:27 +00:00
ea4b6dfd8f Rework constant expr and array handling for objectsize instcombining.
Fix bugs where we would compute out of bounds as in bounds, and where
we couldn't know that the linker could override the size of an array.

Add a few new testcases, change existing testcase to use a private
global array instead of extern.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@95283 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-04 02:55:34 +00:00
ec5ef6d8b0 If we're dealing with a zero-length array, don't lower to any
particular size, we just don't know what the length is yet.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@95266 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-03 23:56:07 +00:00
0c6a8f9eda Recommit this, looks like it wasn't the cause.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@95165 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-03 00:21:58 +00:00
9f34dd305b Hopefully temporarily revert this.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@95154 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-02 23:01:31 +00:00
8334f068c4 Reformat my last patch slightly.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@95147 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-02 22:29:26 +00:00
a6a089cd24 Re-add strcmp and known size object size checking optimization.
Passed bootstrap and nightly test run here.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@95145 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-02 22:10:43 +00:00
39ceb471b7 don't turn (A & (C0?-1:0)) | (B & ~(C0?-1:0)) -> C0 ? A : B
for vectors.  Codegen is generating awful code or segfaulting
in various cases (e.g. PR6204).


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@95058 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-02 02:43:51 +00:00
3b5487e627 LangRef.html says that inttoptr and ptrtoint always use zero-extension
when the cast is extending.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@95046 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-02 01:44:02 +00:00
5f670d4131 cleanups.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@94995 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-01 19:54:45 +00:00
d569561835 fix rdar://7590304, a miscompilation of objc apps on arm. The caller
of objc message send was getting marked arm_apcscc, but the prototype
isn't.  This is fine at runtime because objcmsgsend is implemented in
assembly.  Only turn a mismatched caller and callee into 'unreachable'
if the callee is a definition.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@94986 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-01 18:11:34 +00:00
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
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
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
49db68fba0 Check alignment of loads when deciding whether it is safe to execute them
unconditionally.  Besides checking the offset, also check that the underlying
object is aligned as much as the load itself.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@94875 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-30 04:42:39 +00:00
6ecfccfd55 Use more specific types to avoid casts. No functionality change.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@94863 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-30 00:41:10 +00:00
fb2ea6130d Preserve load alignment in instcombine transformations. I've been unable to
create a testcase where this matters.  The select+load transformation only
occurs when isSafeToLoadUnconditionally is true, and in those situations,
instcombine also changes the underlying objects to be aligned.  This seems
like a good idea regardless, and I've verified that it doesn't pessimize
the subsequent realignment.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@94850 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-29 22:39:21 +00:00
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
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
ac512171ff Having RHSKnownZero and RHSKnownOne be alternative names for KnownZero and KnownOne
(via APInt &RHSKnownZero = KnownZero, etc) seems dangerous and confusing to me: it
is easy not to notice this, and then wonder why KnownZero/RHSKnownZero changed
underneath you when you modified RHSKnownZero/KnownZero etc.  So get rid of this.
No intended functionality change (tested with "make check" + llvm-gcc bootstrap).


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@94802 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-29 06:18:46 +00:00
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
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
43b5f9312d make -fno-rtti the default unless a directory builds with REQUIRES_RTTI.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@94378 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-24 20:43:08 +00:00
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
f7d0d163c5 fix a potential overflow issue Eli pointed out.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@94336 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-23 23:31:46 +00:00
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
29fa5e9886 Keep ignoring pointer-to-pointer bitcasts
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@94194 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-22 19:05:05 +00:00
e73a31f667 Stop building RTTI information for *most* llvm libraries. Notable
missing ones are libsupport, libsystem and libvmcore.  libvmcore is
currently blocked on bugpoint, which uses EH.  Once it stops using
EH, we can switch it off.

This #if 0's out 3 unit tests, because gtest requires RTTI information.
Suggestions welcome on how to fix this.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@94164 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-22 06:49:46 +00:00
a4c77622f7 No need to look through bitcasts for DbgInfoIntrinsic
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@94112 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-21 23:07:15 +00:00
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
d3dc3cc98f Fix comment.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@93831 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-19 01:20:15 +00:00
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
5b39620e2d Fix comment.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@93679 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-17 06:49:03 +00:00
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
53af2d13e7 reenable the piece that turns trunc(zext(x)) -> x even if zext has multiple uses,
codegen has no apparent problem with the trunc version of this, because it turns
into a simple subreg idiom


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@93202 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-11 22:49:40 +00:00
a958cbfe36 Disable folding sext(trunc(x)) -> x (and other similar cast/cast cases) when the
trunc has multiple uses.  Codegen is not able to coalesce the subreg case 
correctly and so this leads to higher register pressure and spilling (see PR5997).

This speeds up 256.bzip2 from 8.60 -> 8.04s on my machine, ~7%.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@93200 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-11 22:45:25 +00:00
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
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
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
8cf4f6f3dd improve comments, remove dead TD argument to CanEvaluateSExtd.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@93143 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-11 02:43:35 +00:00
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
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
aa9c894523 simplify CanEvaluateSExtd to return a bool now that we have a
simpler profitability predicate.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@93111 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-10 07:57:20 +00:00
6954ceec1a the NumCastsRemoved argument to CanEvaluateSExtd is dead, remove it.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@93110 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-10 07:42:21 +00:00
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
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