Commit Graph

880 Commits

Author SHA1 Message Date
Chris Lattner 682a7dc653 Fix a bug compiling PR1978 (perhaps not the only one though) which
was incorrectly simplifying "x == (gep x, 1, i)" into false, even 
though i could be negative.  As it turns out, all the code to 
handle this already existed, we just need to disable the incorrect
optimization case and let the general case handle it.

llvm-svn: 46739
2008-02-05 04:45:32 +00:00
Nick Lewycky 3b59214320 There are some cases where icmp(add) can be folded into a new icmp. Handle them.
llvm-svn: 46687
2008-02-03 16:33:09 +00:00
Nick Lewycky c7a4ba044b Hack on vectors too.
llvm-svn: 46684
2008-02-03 08:19:11 +00:00
Nick Lewycky e6e3a7f6ea Fold away one multiply in instcombine. This would normally be caught in
reassociate anyways, but they could be generated during instcombine's run.

llvm-svn: 46683
2008-02-03 07:42:09 +00:00
Chris Lattner 17819d971e eliminate additions of 0.0 when they are obviously dead. This has to be careful to
avoid turning -0.0 + 0.0 -> -0.0 which is incorrect.

llvm-svn: 46499
2008-01-29 06:52:45 +00:00
Nick Lewycky 8ea81e8ba4 Handle some more combinations of extend and icmp. Fixes PR1940.
llvm-svn: 46431
2008-01-28 03:48:02 +00:00
Chris Lattner 710b441174 Fix PR1932 by disabling an xform invalid for fdiv.
llvm-svn: 46429
2008-01-28 00:58:18 +00:00
Chris Lattner fa1e7eef30 Fold fptrunc(add (fpextend x), (fpextend y)) -> add(x,y), as GCC does.
llvm-svn: 46406
2008-01-27 05:29:54 +00:00
Nick Lewycky f069264164 Enable the fix I just checked in, silly me.
llvm-svn: 46247
2008-01-22 05:42:02 +00:00
Nick Lewycky 78712e5b59 Multiply can be evaluated in a different type, so long as the target type has
a smaller bitwidth.

llvm-svn: 46244
2008-01-22 05:08:48 +00:00
Duncan Sands b5ca2e9fcb I noticed that the trampoline straightening transformation could
drop attributes on varargs call arguments.  Also, it could generate
invalid IR if the transformed call already had the 'nest' attribute
somewhere (this can never happen for code coming from llvm-gcc,
but it's a theoretical possibility).  Fix both problems.

llvm-svn: 45973
2008-01-14 19:52:09 +00:00
Chris Lattner 92bd785323 Turn a memcpy from a double* into a load/store of double instead of
a load/store of i64.  The later prevents promotion/scalarrepl of the
source and dest in many cases.

This fixes the 300% performance regression of the byval stuff on 
stepanov_v1p2.

llvm-svn: 45945
2008-01-14 00:28:35 +00:00
Chris Lattner 57974c8d51 factor memcpy/memmove simplification out to its own SimplifyMemTransfer
method, no functionality change.

llvm-svn: 45944
2008-01-13 23:50:23 +00:00
Chris Lattner 8c5cdddfb9 simplify some code. If we can infer alignment for source and dest that are
greater than memcpy alignment, and if we lower to load/store, use the best 
alignment info we have.

llvm-svn: 45943
2008-01-13 22:30:28 +00:00
Chris Lattner 5a86612d3f simplify some code by adding a InsertBitCastBefore method,
make memmove->memcpy conversion a bit simpler.

llvm-svn: 45942
2008-01-13 22:23:22 +00:00
Chris Lattner 5bc253c8f2 Fix PR1907, a nasty miscompilation because instcombine didn't
realize that ne & sgt  was a signed comparison (it was only 
looking at whether the left compare was signed).

llvm-svn: 45937
2008-01-13 20:59:02 +00:00
Duncan Sands 781f6549db When turning a call to a bitcast function into a direct call,
if this becomes a varargs call then deal correctly with any
parameter attributes on the newly vararg call arguments.

llvm-svn: 45931
2008-01-13 08:02:44 +00:00
Chris Lattner 2940c5c56d Implement PR1795, an instcombine hack for forming GEPs with integer pointer arithmetic.
llvm-svn: 45745
2008-01-08 07:23:51 +00:00
Duncan Sands b18c30acec Small cleanup for handling of type/parameter attribute
incompatibility.

llvm-svn: 45704
2008-01-07 17:16:06 +00:00
Duncan Sands 404eb05247 The transform that tries to turn calls to bitcast functions into
direct calls bails out unless caller and callee have essentially
equivalent parameter attributes.  This is illogical - the callee's
attributes should be of no relevance here.  Rework the logic, which
incidentally fixes a crash when removed arguments have attributes.

llvm-svn: 45658
2008-01-06 18:27:01 +00:00
Duncan Sands 55e5090fe8 When transforming a call to a bitcast function into
a direct call with cast parameters and cast return
value (if any), instcombine was prepared to cast any
non-void return value into any other, whether castable
or not.  Add a new predicate for testing whether casting
is valid, and check it both for the return value and
(as a cleanup) for the parameters.

llvm-svn: 45657
2008-01-06 10:12:28 +00:00
Chris Lattner e666bc272d remove a couple more unsafe xforms in the face of overflow.
llvm-svn: 45613
2008-01-05 01:22:42 +00:00
Chris Lattner db026d703b remove the (x-y) < 0 comparison xform, it miscompiles
things that are not equality comparisons, for example:
   (2147479553+4096)-2147479553 < 0    !=   (2147479553+4096) < 2147479553

llvm-svn: 45612
2008-01-05 01:18:20 +00:00
Chris Lattner f3ebc3f3d2 Remove attribution from file headers, per discussion on llvmdev.
llvm-svn: 45418
2007-12-29 20:36:04 +00:00
Christopher Lamb b053b80b79 Disable null pointer folding transforms for non-generic address spaces. This should probably be a target-specific predicate based on address space. That way for targets where this isn't applicable the predicate can be optimized away.
llvm-svn: 45403
2007-12-29 07:56:53 +00:00
Owen Anderson 7363914ef7 Repair a transform that Chris noticed a bug in. Thanks to Nicholas for pointing out my stupid mistakes when writing this patch. :-)
llvm-svn: 45384
2007-12-28 07:42:12 +00:00
Chris Lattner 5179819beb disable this instcombine xform, it miscompiles:
define i32 @main() {
entry:
	%z = alloca i32		; <i32*> [#uses=2]
	store i32 0, i32* %z
	%tmp = load i32* %z		; <i32> [#uses=1]
	%sub = sub i32 %tmp, 1		; <i32> [#uses=1]
	%cmp = icmp ult i32 %sub, 0		; <i1> [#uses=1]
	%retval = select i1 %cmp, i32 1, i32 0		; <i32> [#uses=1]
	ret i32 %retval
}

into ret 1, instead of ret 0.

Christopher, please investigate.

llvm-svn: 45383
2007-12-28 06:24:31 +00:00
Chris Lattner 74b2ab59fd implement InstCombine/shift-trunc-shift.ll. This allows
us to compile:
#include <math.h>
int t1(double d) { return signbit(d); }

into:

_t1:
	movd	%xmm0, %rax
	shrq	$63, %rax
	ret

instead of:

_t1:
	movd	%xmm0, %rax
	shrq	$32, %rax
	shrl	$31, %eax
	ret

on x86-64.

llvm-svn: 45311
2007-12-22 09:07:47 +00:00
Christopher Lamb 7d82bc46b8 Implement review feedback, including additional transforms
(icmp slt (sub A B) 1) -> (icmp sle A B)
icmp sgt (sub A B) -1) -> (icmp sge A B)

and add testcase.

llvm-svn: 45256
2007-12-20 07:21:11 +00:00
Chris Lattner 16a51da0e2 simplify this code with the new m_Zero() pattern. Make sure the select only
has a single use, and generalize it to not require N to be a constant.

llvm-svn: 45250
2007-12-20 01:56:58 +00:00
Duncan Sands aa31b92508 When inlining through an 'nounwind' call, mark inlined
calls 'nounwind'.  It is important for correct C++
exception handling that nounwind markings do not get
lost, so this transformation is actually needed for
correctness.

llvm-svn: 45218
2007-12-19 21:13:37 +00:00
Christopher Lamb f00ac6dd93 Fold subtracts into integer compares vs. zero. This improves generate code for this case on X86
from
_foo:
        movl    $99, %ecx
        movl    4(%esp), %eax
        subl    %eax, %ecx
        xorl    %edx, %edx
        testl   %ecx, %ecx
        cmovs   %edx, %eax
        ret

to
_foo:
        xorl    %ecx, %ecx
        movl    4(%esp), %eax
        cmpl    $99, %eax
        cmovg   %ecx, %eax
        ret

llvm-svn: 45173
2007-12-18 21:32:20 +00:00
Christopher Lamb b7016c53d1 Fix comments
llvm-svn: 45170
2007-12-18 20:33:11 +00:00
Christopher Lamb 74dbad9216 Remove an orthogonal transformation of the selection condition from my most recent submission.
llvm-svn: 45169
2007-12-18 20:30:28 +00:00
Duncan Sands 3353ed09ac Rename isNoReturn to doesNotReturn, and isNoUnwind to
doesNotThrow.

llvm-svn: 45160
2007-12-18 09:59:50 +00:00
Christopher Lamb 30291f4a30 Fix typos.
llvm-svn: 45159
2007-12-18 09:45:40 +00:00
Christopher Lamb 8b09a464b4 Fold certain additions through selects (and their compares) so as to eliminate subtractions. This code is often produced by the SMAX expansion in SCEV.
This implements test/Transforms/InstCombine/2007-12-18-AddSelCmpSub.ll

llvm-svn: 45158
2007-12-18 09:34:41 +00:00
Christopher Lamb edf0788758 Change the PointerType api for creating pointer types. The old functionality of PointerType::get() has become PointerType::getUnqual(), which returns a pointer in the generic address space. The new prototype of PointerType::get() requires both a type and an address space.
llvm-svn: 45082
2007-12-17 01:12:55 +00:00
Duncan Sands 8e4847ee95 Make instcombine promote inline asm calls to 'nounwind'
calls.  Remove special casing of inline asm from the
inliner.  There is a potential problem: the verifier
rejects invokes of inline asm (not sure why).  If an
asm call is not marked "nounwind" in some .ll, and
instcombine is not run, but the inliner is run, then
an illegal module will be created.  This is bad but
I'm not sure what the best approach is.  I'm tempted
to remove the check in the verifier...

llvm-svn: 45073
2007-12-16 15:51:49 +00:00
Wojciech Matyjewicz 309e5a723b 1. "Upgrage" comments.
2. Using zero-extended value of Scale and unsigned division is safe provided
   that Scale doesn't have the sign bit set.
   Previously these 2 instructions:
        %p = bitcast [100 x {i8,i8,i8}]* %x to i8*
        %q = getelementptr i8* %p, i32 -4
   were combined into:
        %q = getelementptr [100 x { i8, i8, i8 }]* %x, i32 0,
               i32 1431655764, i32 0
   what was incorrect.

llvm-svn: 44936
2007-12-12 15:21:32 +00:00
Chris Lattner d2bbbabbfb simplify some code.
llvm-svn: 44655
2007-12-06 06:25:04 +00:00
Chris Lattner 0ccb663cca move some ashr-specific code out of commonShiftTransforms into visitAShr.
llvm-svn: 44650
2007-12-06 01:59:46 +00:00
Duncan Sands ad0ea2d430 Fix PR1146: parameter attributes are longer part of
the function type, instead they belong to functions
and function calls.  This is an updated and slightly
corrected version of Reid Spencer's original patch.
The only known problem is that auto-upgrading of
bitcode files doesn't seem to work properly (see
test/Bitcode/AutoUpgradeIntrinsics.ll).  Hopefully
a bitcode guru (who might that be? :) ) will fix it.

llvm-svn: 44359
2007-11-27 13:23:08 +00:00
Chris Lattner c00e8adfe0 Implement PR1822
llvm-svn: 44318
2007-11-25 21:27:53 +00:00
Duncan Sands 185eeac0f8 Fix PR1816. If a bitcast of a function only exists because of a
trivial difference in function attributes, allow calls to it to
be converted to direct calls.  Based on a patch by Török Edwin.
While there, move the various lists of mutually incompatible
parameters etc out of the verifier and into ParameterAttributes.h.

llvm-svn: 44315
2007-11-25 14:10:56 +00:00
Chris Lattner 0cf083815a add a comment.
llvm-svn: 44293
2007-11-23 22:35:18 +00:00
Chris Lattner 1985d96dc9 Fix PR1817.
llvm-svn: 44284
2007-11-22 23:47:13 +00:00
Chris Lattner c53b18362a Fix PR1800 by correcting mistaken logic.
llvm-svn: 44188
2007-11-16 06:04:17 +00:00
Andrew Lenharth 19ca5c7021 Better check
llvm-svn: 43897
2007-11-08 18:45:15 +00:00
Andrew Lenharth 8cf11aa330 Fix PR1780
llvm-svn: 43893
2007-11-08 17:39:28 +00:00