Chris Lattner
be97b4e9ab
Fix stupid bug in my checkin yesterday
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@13429 91177308-0d34-0410-b5e6-96231b3b80d8
2004-05-08 22:41:42 +00:00
Chris Lattner
620ce14666
Implement folding of GEP's like:
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%tmp.0 = getelementptr [50 x sbyte]* %ar, uint 0, int 5 ; <sbyte*> [#uses=2]
%tmp.7 = getelementptr sbyte* %tmp.0, int 8 ; <sbyte*> [#uses=1]
together. This patch actually allows us to simplify and generalize the code.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@13415 91177308-0d34-0410-b5e6-96231b3b80d8
2004-05-07 22:09:22 +00:00
Chris Lattner
546516c3c0
Fix PR336: The instcombine pass asserts when visiting load instruction
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@13400 91177308-0d34-0410-b5e6-96231b3b80d8
2004-05-07 15:35:56 +00:00
Chris Lattner
b9110c61fb
Do not mark instructions in unreachable sections of the function as live.
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This fixes PR332 and ADCE/2004-05-04-UnreachableBlock.llx
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@13349 91177308-0d34-0410-b5e6-96231b3b80d8
2004-05-04 17:00:46 +00:00
Chris Lattner
32ed46b36e
Minor efficiency tweak, suggested by Patrick Meredith
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@13341 91177308-0d34-0410-b5e6-96231b3b80d8
2004-05-04 15:19:33 +00:00
Chris Lattner
00d513182d
Make sure to reprocess instructions used by deleted instructions to avoid
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missing opportunities for combination.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@13309 91177308-0d34-0410-b5e6-96231b3b80d8
2004-05-01 23:27:23 +00:00
Chris Lattner
216d4d85fd
Make sure the instruction combiner doesn't lose track of instructions
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when replacing them, missing the opportunity to do simplifications
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@13308 91177308-0d34-0410-b5e6-96231b3b80d8
2004-05-01 23:19:52 +00:00
Chris Lattner
c1526a9da1
Fix a major pessimization in the instcombiner. If an allocation instruction
...
is only used by a cast, and the casted type is the same size as the original
allocation, it would eliminate the cast by folding it into the allocation.
Unfortunately, it was placing the new allocation instruction right before
the cast, which could pull (for example) alloca instructions into the body
of a function. This turns statically allocatable allocas into expensive
dynamically allocated allocas, which is bad bad bad.
This fixes the problem by placing the new allocation instruction at the same
place the old one was, duh. :)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@13289 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-30 04:37:52 +00:00
Chris Lattner
6ffe551f65
Changes to fix up the inst_iterator to pass to boost iterator checks. This
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patch was graciously contributed by Vladimir Prus.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@13185 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-27 15:13:33 +00:00
Chris Lattner
83a2e6e4a1
Instcombine X/-1 --> 0-X
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@13172 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-26 14:01:59 +00:00
Chris Lattner
4a7553e2da
Move the scev expansion code into this pass, where it belongs. There is
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still room for cleanup, but at least the code modification is out of the
analysis now.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@13135 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-23 21:29:48 +00:00
Chris Lattner
b4782d13d1
Disable a previous patch that was causing indvars to loop infinitely :(
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@13108 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-22 15:12:36 +00:00
Chris Lattner
fcb81f5f4c
Fix an extremely serious thinko I made in revision 1.60 of this file.
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@13106 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-22 14:59:40 +00:00
Chris Lattner
1363e85df7
Implement a todo, rewriting all possible scev expressions inside of the
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loop. This eliminates the extra add from the previous case, but it's
not clear that this will be a performance win overall. Tommorows test
results will tell. :)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@13103 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-21 23:36:08 +00:00
Chris Lattner
4e5f03602c
This code really wants to iterate over the OPERANDS of an instruction, not
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over its USES. If it's dead it doesn't have any uses! :)
Thanks to the fabulous and mysterious Bill Wendling for pointing this out. :)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@13102 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-21 22:29:37 +00:00
Chris Lattner
5d461d20ae
Implement a fixme. The helps loops that have induction variables of different
...
types in them. Instead of creating an induction variable for all types, it
creates a single induction variable and casts to the other sizes. This generates
this code:
no_exit: ; preds = %entry, %no_exit
%indvar = phi uint [ %indvar.next, %no_exit ], [ 0, %entry ] ; <uint> [#uses=4]
*** %j.0.0 = cast uint %indvar to short ; <short> [#uses=1]
%indvar = cast uint %indvar to int ; <int> [#uses=1]
%tmp.7 = getelementptr short* %P, uint %indvar ; <short*> [#uses=1]
store short %j.0.0, short* %tmp.7
%inc.0 = add int %indvar, 1 ; <int> [#uses=2]
%tmp.2 = setlt int %inc.0, %N ; <bool> [#uses=1]
%indvar.next = add uint %indvar, 1 ; <uint> [#uses=1]
br bool %tmp.2, label %no_exit, label %loopexit
instead of:
no_exit: ; preds = %entry, %no_exit
%indvar = phi ushort [ %indvar.next, %no_exit ], [ 0, %entry ] ; <ushort> [#uses=2]
*** %indvar = phi uint [ %indvar.next, %no_exit ], [ 0, %entry ] ; <uint> [#uses=3]
%indvar = cast uint %indvar to int ; <int> [#uses=1]
%indvar = cast ushort %indvar to short ; <short> [#uses=1]
%tmp.7 = getelementptr short* %P, uint %indvar ; <short*> [#uses=1]
store short %indvar, short* %tmp.7
%inc.0 = add int %indvar, 1 ; <int> [#uses=2]
%tmp.2 = setlt int %inc.0, %N ; <bool> [#uses=1]
%indvar.next = add uint %indvar, 1
*** %indvar.next = add ushort %indvar, 1
br bool %tmp.2, label %no_exit, label %loopexit
This is an improvement in register pressure, but probably doesn't happen that
often.
The more important fix will be to get rid of the redundant add.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@13101 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-21 22:22:01 +00:00
Chris Lattner
c99acc3709
Fix PR325
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@13081 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-20 20:26:03 +00:00
Chris Lattner
18f16094c2
Initial checkin of a simple loop unswitching pass. It still needs work,
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but it's a start, and seems to do it's basic job.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@13068 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-19 18:07:02 +00:00
Chris Lattner
5864aebe92
Add #include
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@13057 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-19 03:01:23 +00:00
Chris Lattner
3280f7bd55
Move isLoopInvariant to the Loop class
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@13051 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-18 22:46:08 +00:00
Chris Lattner
5fa802fe27
Loop exit sets are no longer explicitly held, they are dynamically computed on demand.
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@13046 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-18 22:15:13 +00:00
Chris Lattner
f1ab4b4eac
Change the ExitBlocks list from being explicitly contained in the Loop
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structure to being dynamically computed on demand. This makes updating
loop information MUCH easier.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@13045 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-18 22:14:10 +00:00
Chris Lattner
e3a55865bb
Reduce the unrolling limit
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@13040 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-18 18:06:14 +00:00
Chris Lattner
cc43909bb6
If the preheader of the loop was the entry block of the function, make sure
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that the exit block of the loop becomes the new entry block of the function.
This was causing a verifier assertion on 252.eon.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@13039 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-18 17:38:42 +00:00
Chris Lattner
998f44f859
Be much more careful about how we update instructions outside of the loop
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using instructions inside of the loop. This should fix the MishaTest failure
from last night.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@13038 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-18 17:32:39 +00:00
Chris Lattner
50ca0a195a
After unrolling our single basic block loop, fold it into the preheader and exit
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block. The primary motivation for doing this is that we can now unroll nested loops.
This makes a pretty big difference in some cases. For example, in 183.equake,
we are now beating the native compiler with the CBE, and we are a lot closer
with LLC.
I'm now going to play around a bit with the unroll factor and see what effect
it really has.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@13034 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-18 06:27:43 +00:00
Chris Lattner
9c2cc4626b
Fix a bug: this does not preserve the CFG!
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While we're at it, add support for updating loop information correctly.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@13033 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-18 05:38:37 +00:00
Chris Lattner
83bf2880c3
Initial checkin of a simple loop unroller. This pass is extremely basic and
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limited. Even in it's extremely simple state (it can only *fully* unroll single
basic block loops that execute a constant number of times), it already helps improve
performance a LOT on some benchmarks, particularly with the native code generators.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@13028 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-18 05:20:17 +00:00
Chris Lattner
3c85eef81a
Make the tail duplication threshold accessible from the command line instead of hardcoded
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@13025 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-18 00:52:43 +00:00
Chris Lattner
20aa098ba6
If the loop executes a constant number of times, try a bit harder to replace
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exit values.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@13018 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-17 18:44:09 +00:00
Chris Lattner
4f1134e51a
Fix a HUGE pessimization on X86. The indvars pass was taking this
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(familiar) function:
int _strlen(const char *str) {
int len = 0;
while (*str++) len++;
return len;
}
And transforming it to use a ulong induction variable, because the type of
the pointer index was left as a constant long. This is obviously very bad.
The fix is to shrink long constants in getelementptr instructions to intptr_t,
making the indvars pass insert a uint induction variable, which is much more
efficient.
Here's the before code for this function:
int %_strlen(sbyte* %str) {
entry:
%tmp.13 = load sbyte* %str ; <sbyte> [#uses=1]
%tmp.24 = seteq sbyte %tmp.13, 0 ; <bool> [#uses=1]
br bool %tmp.24, label %loopexit, label %no_exit
no_exit: ; preds = %entry, %no_exit
*** %indvar = phi uint [ %indvar.next, %no_exit ], [ 0, %entry ] ; <uint> [#uses=2]
*** %indvar = phi ulong [ %indvar.next, %no_exit ], [ 0, %entry ] ; <ulong> [#uses=2]
%indvar1 = cast ulong %indvar to uint ; <uint> [#uses=1]
%inc.02.sum = add uint %indvar1, 1 ; <uint> [#uses=1]
%inc.0.0 = getelementptr sbyte* %str, uint %inc.02.sum ; <sbyte*> [#uses=1]
%tmp.1 = load sbyte* %inc.0.0 ; <sbyte> [#uses=1]
%tmp.2 = seteq sbyte %tmp.1, 0 ; <bool> [#uses=1]
%indvar.next = add ulong %indvar, 1 ; <ulong> [#uses=1]
%indvar.next = add uint %indvar, 1 ; <uint> [#uses=1]
br bool %tmp.2, label %loopexit.loopexit, label %no_exit
loopexit.loopexit: ; preds = %no_exit
%indvar = cast uint %indvar to int ; <int> [#uses=1]
%inc.1 = add int %indvar, 1 ; <int> [#uses=1]
ret int %inc.1
loopexit: ; preds = %entry
ret int 0
}
Here's the after code:
int %_strlen(sbyte* %str) {
entry:
%inc.02 = getelementptr sbyte* %str, uint 1 ; <sbyte*> [#uses=1]
%tmp.13 = load sbyte* %str ; <sbyte> [#uses=1]
%tmp.24 = seteq sbyte %tmp.13, 0 ; <bool> [#uses=1]
br bool %tmp.24, label %loopexit, label %no_exit
no_exit: ; preds = %entry, %no_exit
*** %indvar = phi uint [ %indvar.next, %no_exit ], [ 0, %entry ] ; <uint> [#uses=3]
%indvar = cast uint %indvar to int ; <int> [#uses=1]
%inc.0.0 = getelementptr sbyte* %inc.02, uint %indvar ; <sbyte*> [#uses=1]
%inc.1 = add int %indvar, 1 ; <int> [#uses=1]
%tmp.1 = load sbyte* %inc.0.0 ; <sbyte> [#uses=1]
%tmp.2 = seteq sbyte %tmp.1, 0 ; <bool> [#uses=1]
%indvar.next = add uint %indvar, 1 ; <uint> [#uses=1]
br bool %tmp.2, label %loopexit, label %no_exit
loopexit: ; preds = %entry, %no_exit
%len.0.1 = phi int [ 0, %entry ], [ %inc.1, %no_exit ] ; <int> [#uses=1]
ret int %len.0.1
}
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@13016 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-17 18:16:10 +00:00
Chris Lattner
f50af088f1
Even if there are not any induction variables in the loop, if we can compute
...
the trip count for the loop, insert one so that we can canonicalize the exit
condition.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@13015 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-17 18:08:33 +00:00
Chris Lattner
657253119e
Fix some really nasty dominance bugs that were exposed by my patch to
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make the verifier more strict. This fixes building zlib
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@13002 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-16 18:08:07 +00:00
Chris Lattner
006118fe8c
Fix some of the strange CBE-only failures that happened last night.
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12980 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-16 06:03:17 +00:00
Chris Lattner
d244057a48
Fix a bug in the previous checkin: if the exit block is not the same as
...
the back-edge block, we must check the preincremented value.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12968 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-15 20:26:22 +00:00
Chris Lattner
59fdaeeae8
Change the canonical induction variable that we insert.
...
Instead of producing code like this:
Loop:
X = phi 0, X2
...
X2 = X + 1
if (X != N-1) goto Loop
We now generate code that looks like this:
Loop:
X = phi 0, X2
...
X2 = X + 1
if (X2 != N) goto Loop
This has two big advantages:
1. The trip count of the loop is now explicit in the code, allowing
the direct implementation of Loop::getTripCount()
2. This reduces register pressure in the loop, and allows X and X2 to be
put into the same register.
As a consequence of the second point, the code we generate for loops went
from:
.LBB2: # no_exit.1
...
mov %EDI, %ESI
inc %EDI
cmp %ESI, 2
mov %ESI, %EDI
jne .LBB2 # PC rel: no_exit.1
To:
.LBB2: # no_exit.1
...
inc %ESI
cmp %ESI, 3
jne .LBB2 # PC rel: no_exit.1
... which has two fewer moves, and uses one less register.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12961 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-15 15:21:43 +00:00
Chris Lattner
d9955aaa61
ADd a trivial instcombine: load null -> null
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12940 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-14 03:28:36 +00:00
Chris Lattner
58b7b08ad7
Add SCCP support for constant folding calls, implementing:
...
test/Regression/Transforms/SCCP/calltest.ll
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12921 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-13 19:43:54 +00:00
Chris Lattner
4647b7cd69
Constant propagation should remove the dead instructions
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12917 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-13 19:28:20 +00:00
Chris Lattner
1708d12916
Add support for removing invoke instructions
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12858 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-12 05:15:13 +00:00
Chris Lattner
fbede52af4
Fix a bug in my select transformation
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12826 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-11 01:39:19 +00:00
Chris Lattner
adb7c0de39
Update the value numbering interface.
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12824 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-10 22:33:34 +00:00
Chris Lattner
d76956d444
Implement InstCombine/select.ll:test13*
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12821 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-10 22:21:27 +00:00
Chris Lattner
66331a4e33
Implement InstCombine/add.ll:test20
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Canonicalize add of sign bit constant into a xor
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12819 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-10 22:01:55 +00:00
Chris Lattner
38e66bd9d1
Rewrite the GCSE pass to be *substantially* simpler, a bit more efficient,
...
and a bit more powerful
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12817 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-10 21:11:11 +00:00
Chris Lattner
326c0f3013
Fix spurious warning in release mode
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12816 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-10 19:15:56 +00:00
Chris Lattner
a5f4103931
Simplify code a bit, and fix a bug that was breaking perlbmk
...
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12814 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-10 18:06:21 +00:00
Chris Lattner
562cb66b84
Fix a bug in my checkin last night that was breaking programs using invoke.
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12813 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-10 16:53:29 +00:00
Chris Lattner
27c694bacb
Fix previous patch
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12811 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-10 07:27:48 +00:00
Chris Lattner
17177601fb
Correctly update counters
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12810 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-10 07:02:02 +00:00