Commit Graph

169 Commits

Author SHA1 Message Date
Nuno Lopes
0fd518beb3 PHINode::hasConstantValue(): return undef if the PHI is fully recursive.
Thanks Duncan for the idea

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@159687 91177308-0d34-0410-b5e6-96231b3b80d8
2012-07-03 21:15:40 +00:00
Dan Gohman
b401e3bd16 Teach DeadStoreElimination to eliminate exit-block stores with phi addresses.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@156558 91177308-0d34-0410-b5e6-96231b3b80d8
2012-05-10 18:57:38 +00:00
Duncan Sands
5ff30e70f8 Just mark the sign bit as known zero, rather than any other irrelevant bits
known zero in the LHS.  Fixes PR12541.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@155818 91177308-0d34-0410-b5e6-96231b3b80d8
2012-04-30 11:56:58 +00:00
Chandler Carruth
c0d18b6696 Fix ValueTracking to conclude that debug intrinsics are safe to
speculate. Without this, loop rotate (among many other places) would
suddenly stop working in the presence of debug info. I found this
looking at loop rotate, and have augmented its tests with a reduction
out of a very hot loop in yacr2 where failing to do this rotation costs
sometimes more than 10% in runtime performance, perturbing numerous
downstream optimizations.

This should have no impact on performance without debug info, but the
change in performance when debug info is enabled can be extreme. As
a consequence (and this how I got to this yak) any profiling of
performance problems should be treated with deep suspicion -- they may
have been wildly innacurate of debug info was enabled for profiling. =/
Just a heads up.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@154263 91177308-0d34-0410-b5e6-96231b3b80d8
2012-04-07 19:22:18 +00:00
Rafael Espindola
26c8dcc692 Always compute all the bits in ComputeMaskedBits.
This allows us to keep passing reduced masks to SimplifyDemandedBits, but
know about all the bits if SimplifyDemandedBits fails. This allows instcombine
to simplify cases like the one in the included testcase.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@154011 91177308-0d34-0410-b5e6-96231b3b80d8
2012-04-04 12:51:34 +00:00
Rafael Espindola
95d594cac3 Teach CodeGen's version of computeMaskedBits to understand the range metadata.
This is the CodeGen equivalent of r153747. I tested that there is not noticeable
performance difference with any combination of -O0/-O2 /-g when compiling
gcc as a single compilation unit.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@153817 91177308-0d34-0410-b5e6-96231b3b80d8
2012-03-31 18:14:00 +00:00
Rafael Espindola
7c7121edb9 Add computeMaskedBitsLoad back, as it was the change to instsimplify that
caused the slowdown last time.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@153747 91177308-0d34-0410-b5e6-96231b3b80d8
2012-03-30 15:52:11 +00:00
Chad Rosier
89e2b318e2 Revert r153521 as it's causing large regressions on the nightly testers.
Original commit message for r153521 (aka r153423):
Use the new range metadata in computeMaskedBits and add a new optimization to
instruction simplify that lets us remove an and when loding a boolean value.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@153587 91177308-0d34-0410-b5e6-96231b3b80d8
2012-03-28 18:42:50 +00:00
Chad Rosier
d23a64cc16 Reapply r153423; the original commit was fine. The failing test, distray, had
undefined behavior, which Rafael was kind enough to fix.

Original commit message for r153423:
Use the new range metadata in computeMaskedBits and add a new optimization to
instruction simplify that lets us remove an and when loding a boolean value.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@153521 91177308-0d34-0410-b5e6-96231b3b80d8
2012-03-27 17:44:52 +00:00
Chad Rosier
cde6650bd0 Revert r153423 as this is causing failures on our internal nightly testers.
Original commit message:
Use the new range metadata in computeMaskedBits and add a new optimization to
instruction simplify that lets us remove an and when loading a boolean value.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@153452 91177308-0d34-0410-b5e6-96231b3b80d8
2012-03-26 18:07:14 +00:00
Rafael Espindola
7ddcd35d6b Use the new range metadata in computeMaskedBits and add a new optimization to
instruction simplify that lets us remove an and when loding a boolean value.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@153423 91177308-0d34-0410-b5e6-96231b3b80d8
2012-03-26 01:44:11 +00:00
Nick Lewycky
f201a06662 Factor out the multiply analysis code in ComputeMaskedBits and apply it to the
overflow checking multiply intrinsic as well.

Add a test for this, updating the test from grep to FileCheck.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@153028 91177308-0d34-0410-b5e6-96231b3b80d8
2012-03-18 23:28:48 +00:00
Nick Lewycky
00cbccceb3 Factor out the analysis of addition and subtraction in ComputeMaskedBits. Reuse
it to analyze extractvalue(llvm.[us](add|sub).with.overflow.*) intrinsics!


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@152398 91177308-0d34-0410-b5e6-96231b3b80d8
2012-03-09 09:23:50 +00:00
Nick Lewycky
891495e676 No functionality change. Type::isSized() can be expensive, so avoid calling it
until after other inexpensive tests.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@152195 91177308-0d34-0410-b5e6-96231b3b80d8
2012-03-07 02:27:53 +00:00
Eli Friedman
923bb4117a A few more cases of missing masking in ComputeMaskedBits; found by inspection.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@152070 91177308-0d34-0410-b5e6-96231b3b80d8
2012-03-05 23:22:40 +00:00
Eli Friedman
049d08f5c9 Make sure we don't return bits outside the mask in ComputeMaskedBits. PR12189.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@152066 91177308-0d34-0410-b5e6-96231b3b80d8
2012-03-05 23:09:40 +00:00
Chris Lattner
7302d80490 Remove some dead code and tidy things up now that vectors use ConstantDataVector
instead of always using ConstantVector.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@149912 91177308-0d34-0410-b5e6-96231b3b80d8
2012-02-06 21:56:39 +00:00
Bill Wendling
8833ef03b9 [unwind removal] Remove all of the code for the dead 'unwind' instruction. There
were no 'unwind' instructions being generated before this, so this is in effect
a no-op.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@149906 91177308-0d34-0410-b5e6-96231b3b80d8
2012-02-06 21:44:22 +00:00
Chris Lattner
18c7f80b3e reapply the patches reverted in r149470 that reenable ConstantDataArray,
but with a critical fix to the SelectionDAG code that optimizes copies
from strings into immediate stores: the previous code was stopping reading
string data at the first nul.  Address this by adding a new argument to
llvm::getConstantStringInfo, preserving the behavior before the patch.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@149800 91177308-0d34-0410-b5e6-96231b3b80d8
2012-02-05 02:29:43 +00:00
Argyrios Kyrtzidis
91766fe066 Revert Chris' commits up to r149348 that started causing VMCoreTests unit test to fail.
These are:

r149348
r149351
r149352
r149354
r149356
r149357
r149361
r149362
r149364
r149365

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@149470 91177308-0d34-0410-b5e6-96231b3b80d8
2012-02-01 04:51:17 +00:00
Chris Lattner
f0e1053a63 remove the last vestiges of llvm::GetConstantStringInfo, in CodeGen.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@149356 91177308-0d34-0410-b5e6-96231b3b80d8
2012-01-31 05:09:17 +00:00
Chris Lattner
3ef9cfef13 Change ConstantArray::get to form a ConstantDataArray when possible,
kicking in the big win of ConstantDataArray.  As part of this, change
the implementation of GetConstantStringInfo in ValueTracking to work
with ConstantDataArray (and not ConstantArray) making it dramatically,
amazingly, more efficient in the process and renaming it to 
getConstantStringInfo.

This keeps around a GetConstantStringInfo entrypoint that (grossly)
forwards to getConstantStringInfo and constructs the std::string 
required, but existing clients should move over to 
getConstantStringInfo instead.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@149351 91177308-0d34-0410-b5e6-96231b3b80d8
2012-01-31 04:42:22 +00:00
Chris Lattner
6b0dc92043 progress making the world safe to ConstantDataVector. While
we're at it, allow PatternMatch's "neg" pattern to match integer
vector negations, and enhance ComputeNumSigned bits to handle
shl of vectors.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@149082 91177308-0d34-0410-b5e6-96231b3b80d8
2012-01-26 21:37:55 +00:00
Chris Lattner
a1f00f4d48 use Constant::getAggregateElement to simplify a bunch of code.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@148934 91177308-0d34-0410-b5e6-96231b3b80d8
2012-01-25 06:48:06 +00:00
Chris Lattner
0f193b8a68 Use the right method to get the # elements in a CDS.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@148897 91177308-0d34-0410-b5e6-96231b3b80d8
2012-01-25 01:27:20 +00:00
Chris Lattner
df39028607 teach valuetracking about ConstantDataSequential
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@148790 91177308-0d34-0410-b5e6-96231b3b80d8
2012-01-24 07:54:10 +00:00
Dan Gohman
febaf84017 Generalize isSafeToSpeculativelyExecute to work on arbitrary
Values, rather than just Instructions, since it's interesting
for ConstantExprs too.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@147560 91177308-0d34-0410-b5e6-96231b3b80d8
2012-01-04 23:01:09 +00:00
Benjamin Kramer
55c6d57734 PatternMatch: Introduce a matcher for instructions with the "exact" bit. Use it to simplify a few matchers.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@147403 91177308-0d34-0410-b5e6-96231b3b80d8
2012-01-01 17:55:30 +00:00
Benjamin Kramer
009da05e75 ComputeMaskedBits: Make knownzero computation more aggressive for ctlz with undef zero.
unsigned foo(unsigned x) { return 31 - __builtin_clz(x); }
now compiles into a single "bsrl" instruction on x86.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@147255 91177308-0d34-0410-b5e6-96231b3b80d8
2011-12-24 17:31:46 +00:00
Nick Lewycky
8369687576 Make some intrinsics safe to speculatively execute.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@147036 91177308-0d34-0410-b5e6-96231b3b80d8
2011-12-21 05:52:02 +00:00
Dan Gohman
f042660197 Move Instruction::isSafeToSpeculativelyExecute out of VMCore and
into Analysis as a standalone function, since there's no need for
it to be in VMCore. Also, update it to use isKnownNonZero and
other goodies available in Analysis, making it more precise,
enabling more aggressive optimization.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@146610 91177308-0d34-0410-b5e6-96231b3b80d8
2011-12-14 23:49:11 +00:00
Chad Rosier
dce42b75dc Probably not a good idea to convert a single vector load into a memcpy. We
don't do this now, but add a test case to prevent this from happening in the
future.
Additional test for rdar://9892684

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@145879 91177308-0d34-0410-b5e6-96231b3b80d8
2011-12-06 00:19:08 +00:00
Nadav Rotem
1608769abe Add support for vectors of pointers.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@145801 91177308-0d34-0410-b5e6-96231b3b80d8
2011-12-05 06:29:09 +00:00
Duncan Sands
d3a38ccfbb Fix a theoretical problem (not seen in the wild): if different instances of a
weak variable are compiled by different compilers, such as GCC and LLVM, while
LLVM may increase the alignment to the preferred alignment there is no reason to
think that GCC will use anything more than the ABI alignment.  Since it is the
GCC version that might end up in the final program (as the linkage is weak), it
is wrong to increase the alignment of loads from the global up to the preferred
alignment as the alignment might only be the ABI alignment.

Increasing alignment up to the ABI alignment might be OK, but I'm not totally
convinced that it is.  It seems better to just leave the alignment of weak
globals alone.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@145413 91177308-0d34-0410-b5e6-96231b3b80d8
2011-11-29 18:26:38 +00:00
Eli Friedman
c4c2a02485 Make SelectionDAG::InferPtrAlignment use llvm::ComputeMaskedBits instead of duplicating the logic for globals. Make llvm::ComputeMaskedBits handle GlobalVariables slightly more aggressively, to match what InferPtrAlignment knew how to do.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@145304 91177308-0d34-0410-b5e6-96231b3b80d8
2011-11-28 22:48:22 +00:00
Duncan Sands
a8f5cd3539 Fix a crash in which a multiplication was being reported as being both negative
and positive: positive, because it could be directly computed to be positive;
negative, because the nsw flags means it is either negative or undefined (the
multiplication always overflowed).


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@145104 91177308-0d34-0410-b5e6-96231b3b80d8
2011-11-23 16:26:47 +00:00
Duncan Sands
4604fc7791 A shift of a power of two is a power of two or zero.
For completeness - not spotted in the wild.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@143211 91177308-0d34-0410-b5e6-96231b3b80d8
2011-10-28 18:30:05 +00:00
Duncan Sands
32a43cc0fc Reapply commit 143028 with a fix: the problem was casting a ConstantExpr Mul
using BinaryOperator (which only works for instructions) when it should have
been a cast to OverflowingBinaryOperator (which also works for constants).
While there, correct a few other dubious looking uses of BinaryOperator.
Thanks to Chad Rosier for the testcase.  Original commit message:
My super-optimizer noticed that we weren't folding this expression to
true: (x *nsw x) sgt 0, where x = (y | 1).  This occurs in 464.h264ref.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@143125 91177308-0d34-0410-b5e6-96231b3b80d8
2011-10-27 19:16:21 +00:00
Bob Wilson
090697321b Revert Duncan's r143028 expression folding which appears to be the culprit
behind a compile failure on 483.xalancbmk.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@143102 91177308-0d34-0410-b5e6-96231b3b80d8
2011-10-27 15:47:25 +00:00
Duncan Sands
dd3149d579 The maximum power of 2 dividing a power of 2 is itself. This occurs
in 403.gcc and was spotted by my super-optimizer.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@143054 91177308-0d34-0410-b5e6-96231b3b80d8
2011-10-26 20:55:21 +00:00
Duncan Sands
e8ec225e77 My super-optimizer noticed that we weren't folding this expression to
true: (x *nsw x) sgt 0, where x = (y | 1).  This occurs in 464.h264ref.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@143028 91177308-0d34-0410-b5e6-96231b3b80d8
2011-10-26 15:31:51 +00:00
Nick Lewycky
0cd0fee91e "@string = constant i8 0" is a value i8* string of length zero. Analyze that
correctly in GetStringLength, fixing PR11181!


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@142558 91177308-0d34-0410-b5e6-96231b3b80d8
2011-10-20 00:34:35 +00:00
Frits van Bommel
39b5abf507 Migrate LLVM and Clang to use the new makeArrayRef(...) functions where previously explicit non-default constructors were used.
Mostly mechanical with some manual reformatting.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@135390 91177308-0d34-0410-b5e6-96231b3b80d8
2011-07-18 12:00:32 +00:00
Chris Lattner
db125cfaf5 land David Blaikie's patch to de-constify Type, with a few tweaks.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@135375 91177308-0d34-0410-b5e6-96231b3b80d8
2011-07-18 04:54:35 +00:00
Jay Foad
fc6d3a4986 Convert InsertValueInst and ExtractValueInst APIs to use ArrayRef.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@135040 91177308-0d34-0410-b5e6-96231b3b80d8
2011-07-13 10:26:04 +00:00
Nick Lewycky
99e0b2a8df Move onlyUsedByLifetimeMarkers to ValueTracking so that it can be used by other
passes as well.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@133904 91177308-0d34-0410-b5e6-96231b3b80d8
2011-06-27 04:20:45 +00:00
Chad Rosier
62660310d9 Renamed llvm.x86.sse42.crc32 intrinsics; crc64 doesn't exist.
crc32.[8|16|32] have been renamed to .crc32.32.[8|16|32] and
crc64.[8|16|32] have been renamed to .crc32.64.[8|64].




git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@132163 91177308-0d34-0410-b5e6-96231b3b80d8
2011-05-26 23:13:19 +00:00
Chris Lattner
b3f0673d52 Teach valuetracking that byval arguments with a specified alignment are
aligned.

Teach memcpyopt to not give up all hope when confonted with an underaligned
memcpy feeding an overaligned byval.  If the *source* of the memcpy can be
determined to be adequeately aligned, or if it can be forced to be, we can
eliminate the memcpy.

This addresses PR9794.  We now compile the example into:

define i32 @f(%struct.p* nocapture byval align 8 %q) nounwind ssp {
entry:
  %call = call i32 @g(%struct.p* byval align 8 %q) nounwind
  ret i32 %call
}

in both x86-64 and x86-32 mode.  We still don't get a tailcall though,
because tailcalls apparently can't handle byval.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@131884 91177308-0d34-0410-b5e6-96231b3b80d8
2011-05-23 00:03:39 +00:00
Evan Cheng
cb559c1270 Teach ValueTracking about x86 crc32 intrinsics.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@131861 91177308-0d34-0410-b5e6-96231b3b80d8
2011-05-22 18:25:30 +00:00
Chris Lattner
7a2bdde0a0 Fix a ton of comment typos found by codespell. Patch by
Luis Felipe Strano Moraes!



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@129558 91177308-0d34-0410-b5e6-96231b3b80d8
2011-04-15 05:18:47 +00:00