Commit Graph

3177 Commits

Author SHA1 Message Date
Chris Lattner
97bd89ece3 fix a bug in r121680 that upset the various buildbots.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121687 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-13 05:34:18 +00:00
Chris Lattner
c232a2e559 make these tests a bit less fragile
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121682 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-13 05:10:30 +00:00
Chris Lattner
7312a22ed6 enhance the "change or icmp's into switch" xform to handle one value in an
'or sequence' that it doesn't understand.  This allows us to optimize
something insane like this:

int crud (unsigned char c, unsigned x)
 {
   if(((((((((( (int) c <= 32 ||
                    (int) c == 46) || (int) c == 44)
                  || (int) c == 58) || (int) c == 59) || (int) c == 60)
               || (int) c == 62) || (int) c == 34) || (int) c == 92)
            || (int) c == 39) != 0)
     foo();
 }

into:

define i32 @crud(i8 zeroext %c, i32 %x) nounwind ssp noredzone {
entry:
  %cmp = icmp ult i8 %c, 33
  br i1 %cmp, label %if.then, label %switch.early.test

switch.early.test:                                ; preds = %entry
  switch i8 %c, label %if.end [
    i8 39, label %if.then
    i8 44, label %if.then
    i8 58, label %if.then
    i8 59, label %if.then
    i8 60, label %if.then
    i8 62, label %if.then
    i8 46, label %if.then
    i8 92, label %if.then
    i8 34, label %if.then
  ]

by pulling the < comparison out ahead of the newly formed switch.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121680 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-13 04:50:38 +00:00
Chris Lattner
f5198e7fe3 merge two tests
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121679 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-13 04:45:56 +00:00
Chris Lattner
abf706703f Fix my previous patch to handle a degenerate case that the llvm-gcc
bootstrap buildbot tripped over.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121674 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-13 03:43:57 +00:00
Chris Lattner
61c77449c7 fix a fairly serious oversight with switch formation from
or'd conditions.  Previously we'd compile something like this:

int crud (unsigned char c) {
   return c == 62 || c == 34 || c == 92;
}

into:

  switch i8 %c, label %lor.rhs [
    i8 62, label %lor.end
    i8 34, label %lor.end
  ]

lor.rhs:                                          ; preds = %entry
  %cmp8 = icmp eq i8 %c, 92
  br label %lor.end

lor.end:                                          ; preds = %entry, %entry, %lor.rhs
  %0 = phi i1 [ true, %entry ], [ %cmp8, %lor.rhs ], [ true, %entry ]
  %lor.ext = zext i1 %0 to i32
  ret i32 %lor.ext

which failed to merge the compare-with-92 into the switch.  With this patch
we simplify this all the way to:

  switch i8 %c, label %lor.rhs [
    i8 62, label %lor.end
    i8 34, label %lor.end
    i8 92, label %lor.end
  ]

lor.rhs:                                          ; preds = %entry
  br label %lor.end

lor.end:                                          ; preds = %entry, %entry, %entry, %lor.rhs
  %0 = phi i1 [ true, %entry ], [ false, %lor.rhs ], [ true, %entry ], [ true, %entry ]
  %lor.ext = zext i1 %0 to i32
  ret i32 %lor.ext

which is much better for codegen's switch lowering stuff.  This kicks in 33 times
on 176.gcc (for example) cutting 103 instructions off the generated code.





git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121671 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-13 03:18:54 +00:00
Benjamin Kramer
2f7228b80c Generalize the and-icmp-select instcombine further by allowing selects of the form
(x & 2^n) ? 2^m+C : C

we can offset both arms by C to get the "(x & 2^n) ? 2^m : 0" form, optimize the
select to a shift and apply the offset afterwards.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121609 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-11 10:49:22 +00:00
Benjamin Kramer
20e3b4b380 Factor the (x & 2^n) ? 2^m : 0 instcombine into its own method and generalize it
to catch cases where n != m with a shift.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121608 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-11 09:42:59 +00:00
Chris Lattner
8fdca6a873 enhance memcpyopt to zap memcpy's that have the same src/dst.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121362 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-09 07:45:45 +00:00
Chris Lattner
f7f35467a9 fix PR8753, eliminating a case where we'd infinitely make a
substitution because it doesn't actually change the IR.  Patch by
Jakub Staszak!



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121361 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-09 07:39:50 +00:00
Dan Gohman
d8e0c0438a Really check that the bits that will become zero are actually already zero
before eliminating the operation that zeros them. This fixes rdar://8739316.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121353 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-09 02:52:17 +00:00
Chris Lattner
1945d58025 reapply r121100 with a tweak to constant fold ConstExprs with TargetData
(if available) as we go so that we get simple constantexprs not insane ones.
This fixes the failure of clang/test/CodeGenCXX/virtual-base-ctor.cpp
that the previous iteration of this patch had.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121111 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-07 04:33:29 +00:00
Eric Christopher
6a3e305326 Temporarily revert r121100 as it's causing clang to fail
CodeGenCXX/virtual-base-ctor.cpp.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121102 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-07 02:41:11 +00:00
Chris Lattner
fb431099c5 fix PR8710 - teach global opt that some constantexprs are too complex to
put in a global variable's initializer.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121100 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-07 01:59:32 +00:00
Frits van Bommel
6033b346e2 Implement jump threading of 'indirectbr' by keeping track of whether we're looking for ConstantInt*s or BlockAddress*s.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121066 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-06 23:36:56 +00:00
Chris Lattner
cc10244d77 Fix PR8728, a miscompilation I recently introduced. When optimizing
memcpy's like:
  memcpy(A, B)
  memcpy(A, C)

we cannot delete the first memcpy as dead if A and C might be aliases.
If so, we actually get:

  memcpy(A, B)
  memcpy(A, A)

which is not correct to transform into:

  memcpy(A, A)

This patch was heavily influenced by Jakub Staszak's patch in PR8728, thanks
Jakub!



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@120974 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-06 01:48:06 +00:00
Frits van Bommel
7ac40c3ffa Teach SimplifyCFG to turn
(indirectbr (select cond, blockaddress(@fn, BlockA),
                            blockaddress(@fn, BlockB)))
into
  (br cond, BlockA, BlockB).


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@120943 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-05 18:29:03 +00:00
Chris Lattner
b5a3196f80 fix a bozo bug I introduced in r119930, causing a miscompile of
20040709-1.c from the gcc testsuite.  I was using the size of a
pointer instead of the pointee.  This fixes rdar://8713376


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@120519 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-01 01:24:55 +00:00
Chris Lattner
3161ae1867 Enhance DSE to handle the variable index case in PR8657.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@120498 91177308-0d34-0410-b5e6-96231b3b80d8
2010-11-30 23:43:23 +00:00
Chris Lattner
a04096580a teach DSE to use GetPointerBaseWithConstantOffset to analyze
may-aliasing stores that partially overlap with different base
pointers.  This implements PR6043 and the non-variable part of
PR8657


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@120485 91177308-0d34-0410-b5e6-96231b3b80d8
2010-11-30 23:05:20 +00:00
Chris Lattner
55ee75d571 enhance isRemovable to refuse to delete volatile mem transfers
now that DSE hacks on them.  This fixes a regression I introduced,
by generalizing DSE to hack on transfers.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@120445 91177308-0d34-0410-b5e6-96231b3b80d8
2010-11-30 19:12:10 +00:00
Chris Lattner
cf82dc376a Rewrite the main DSE loop to be written in terms of reasoning
about pairs of AA::Location's instead of looking for MemDep's
"Def" predicate.  This is more powerful and general, handling
memset/memcpy/store all uniformly, and implementing PR8701 and
probably obsoleting parts of memcpyoptimizer.

This also fixes an obscure bug with init.trampoline and i8
stores, but I'm not surprised it hasn't been hit yet.  Enhancing
init.trampoline to carry the size that it stores would allow
DSE to be much more aggressive about optimizing them.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@120406 91177308-0d34-0410-b5e6-96231b3b80d8
2010-11-30 07:23:21 +00:00
Anders Carlsson
303023d9ff Add a puts optimization that converts puts() to putchar('\n').
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@120398 91177308-0d34-0410-b5e6-96231b3b80d8
2010-11-30 06:19:18 +00:00
Anders Carlsson
1d06295583 Fix a typo.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@120394 91177308-0d34-0410-b5e6-96231b3b80d8
2010-11-30 06:03:55 +00:00
Anders Carlsson
2703399041 Rename this test to FPuts.ll since it actually tests fputs.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@120393 91177308-0d34-0410-b5e6-96231b3b80d8
2010-11-30 05:59:26 +00:00
Chris Lattner
d7b6a989a7 remove a use of llvm-dis
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@120383 91177308-0d34-0410-b5e6-96231b3b80d8
2010-11-30 02:04:15 +00:00
Chris Lattner
feea8fb6b4 merge one more away
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@120375 91177308-0d34-0410-b5e6-96231b3b80d8
2010-11-30 01:06:43 +00:00
Chris Lattner
8a2dc0233f I already merged partial-overwrite.ll -> PartialStore.ll
Merge context-sensitive.ll -> simple.ll and upgrade it.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@120374 91177308-0d34-0410-b5e6-96231b3b80d8
2010-11-30 01:05:07 +00:00
Chris Lattner
75aa30bb1c clean up DSE tests, removing some poorly reduced and useless old test,
merging more into other larger .ll files, filecheckizing along the way.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@120373 91177308-0d34-0410-b5e6-96231b3b80d8
2010-11-30 01:00:34 +00:00
Chris Lattner
13815d9d3e enhance basicaa to return "Mod" for a memcpy call when the
queried location doesn't overlap the source, and add a testcase.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@120370 91177308-0d34-0410-b5e6-96231b3b80d8
2010-11-30 00:43:16 +00:00
Chris Lattner
201d1e56bb Teach basicaa that memset's modref set is at worst "mod" and never
contains "ref".

Enhance DSE to use a modref query instead of a store-specific hack
to generalize the "ignore may-alias stores" optimization to handle
memset and memcpy.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@120368 91177308-0d34-0410-b5e6-96231b3b80d8
2010-11-30 00:28:45 +00:00
Chris Lattner
184d1ba738 my previous patch would cause us to start deleting some volatile
stores, fix and add a testcase.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@120363 91177308-0d34-0410-b5e6-96231b3b80d8
2010-11-30 00:12:39 +00:00
Benjamin Kramer
8ad87ab166 Fix some broken CHECK lines.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@120332 91177308-0d34-0410-b5e6-96231b3b80d8
2010-11-29 22:34:55 +00:00
Chris Lattner
e9e973018a fix PR8677, patch by Jakub Staszak!
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@120325 91177308-0d34-0410-b5e6-96231b3b80d8
2010-11-29 21:59:31 +00:00
Frits van Bommel
34ceb4db22 Transform (extractvalue (load P), ...) to (load (gep P, 0, ...)) if the load has no other uses, shrinking the load.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@120323 91177308-0d34-0410-b5e6-96231b3b80d8
2010-11-29 21:56:20 +00:00
Frits van Bommel
d2fe8e0acd Update this test to keep testing the -instcombine transform it's supposed to be testing instead of triggering the improved constant folding for insertvalue and extractvalue.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@120319 91177308-0d34-0410-b5e6-96231b3b80d8
2010-11-29 20:55:40 +00:00
Frits van Bommel
3ee0af3584 Teach ConstantFoldInstruction() how to fold insertvalue and extractvalue.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@120316 91177308-0d34-0410-b5e6-96231b3b80d8
2010-11-29 20:36:52 +00:00
Nick Lewycky
081f80078d Treat a call of function pointer like a load of the pointer when considering
whether the pointer can be replaced with the global variable it is a copy of.
Fixes PR8680.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@120126 91177308-0d34-0410-b5e6-96231b3b80d8
2010-11-24 22:04:20 +00:00
Benjamin Kramer
c21a821e9f The srem -> urem transform is not safe for any divisor that's not a power of two.
E.g. -5 % 5 is 0 with srem and 1 with urem.

Also addresses Frits van Bommel's comments.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@120049 91177308-0d34-0410-b5e6-96231b3b80d8
2010-11-23 20:33:57 +00:00
Benjamin Kramer
b70ebd2aa3 InstCombine: Reduce "X shift (A srem B)" to "X shift (A urem B)" iff B is positive.
This allows to transform the rem in "1 << ((int)x % 8);" to an and.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@120028 91177308-0d34-0410-b5e6-96231b3b80d8
2010-11-23 18:52:42 +00:00
Duncan Sands
5057f38141 Exploit distributive laws (eg: And distributes over Or, Mul over Add, etc) in a
fairly systematic way in instcombine.  Some of these cases were already dealt
with, in which case I removed the existing code.  The case of Add has a bunch of
funky logic which covers some of this plus a few variants (considers shifts to be
a form of multiplication), which I didn't touch.  The simplification performed is:
A*B+A*C -> A*(B+C).  The improvement is to do this in cases that were not already
handled [such as A*B-A*C -> A*(B-C), which was reported on the mailing list], and
also to do it more often by not checking for "only one use" if "B+C" simplifies.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@120024 91177308-0d34-0410-b5e6-96231b3b80d8
2010-11-23 14:23:47 +00:00
Chris Lattner
79b967bd9f duncan's spider sense was right, I completely reversed the condition
on this instcombine xform.  This fixes a miscompilation of 403.gcc.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@119988 91177308-0d34-0410-b5e6-96231b3b80d8
2010-11-23 02:42:04 +00:00
Benjamin Kramer
93f8455d73 InstCombine: Implement X - A*-B -> X + A*B.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@119984 91177308-0d34-0410-b5e6-96231b3b80d8
2010-11-22 20:31:27 +00:00
Duncan Sands
a63395a30f If a GEP index simply advances by multiples of a type of zero size,
then replace the index with zero.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@119974 91177308-0d34-0410-b5e6-96231b3b80d8
2010-11-22 16:32:50 +00:00
Duncan Sands
e60d79faf7 Add a rather pointless InstructionSimplify transform, inspired by recent constant
folding improvements: if P points to a type of size zero, turn "gep P, N" into "P".
More generally, if a gep index type has size zero, instcombine could replace the
index with zero, but that is not done here.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@119942 91177308-0d34-0410-b5e6-96231b3b80d8
2010-11-21 13:53:09 +00:00
Chris Lattner
f6f1f062cc implement PR8576, deleting dead stores with intervening may-alias stores.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@119927 91177308-0d34-0410-b5e6-96231b3b80d8
2010-11-21 07:34:32 +00:00
Chris Lattner
b7dfb970e6 file checkize
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@119926 91177308-0d34-0410-b5e6-96231b3b80d8
2010-11-21 07:32:40 +00:00
Chris Lattner
75d8f599e7 optimize:
void a(int x) { if (((1<<x)&8)==0) b(); }

into "x != 3", which occurs over 100 times in 403.gcc but in no
other program in llvm-test.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@119922 91177308-0d34-0410-b5e6-96231b3b80d8
2010-11-21 06:44:42 +00:00
Chris Lattner
2f5f90ad3e Implement PR8644: forwarding a memcpy value to a byval,
allowing the memcpy to be eliminated.

Unfortunately, the requirements on byval's without explicit 
alignment are really weak and impossible to predict in the 
mid-level optimizer, so this doesn't kick in much with current
frontends.  The fix is to change clang to set alignment on all
byval arguments.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@119916 91177308-0d34-0410-b5e6-96231b3b80d8
2010-11-21 00:28:59 +00:00
Owen Anderson
563d9bdc84 Add a test for CodeGenPrepare's ability to look through PHI nodes when performing
addressing mode folding, introduced in r119853.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@119857 91177308-0d34-0410-b5e6-96231b3b80d8
2010-11-19 22:34:53 +00:00