a62b01dc37
restructure this a bit. Initialize the WeakVH with "I", the
...
instruction *after* the store. The store will always be deleted
if the transformation kicks in, so we'd do an N^2 scan of every
loop block. Whoops.
llvm-svn: 122805
2011-01-04 07:27:30 +00:00
0ba473c218
use the very-handy getTruncateOrZeroExtend helper function, and
...
stop setting NSW: signed overflow is possible. Thanks to Dan
for pointing these out.
llvm-svn: 122790
2011-01-04 00:06:55 +00:00
0839d3930a
Fix comment.
...
llvm-svn: 122788
2011-01-03 23:51:56 +00:00
02a9776b64
reduce redundancy in the hashing code and other misc cleanups.
...
llvm-svn: 122720
2011-01-03 01:10:08 +00:00
8fac5db251
add DEBUG and -stats output to earlycse.
...
Teach it to CSE the rest of the non-side-effecting instructions.
llvm-svn: 122716
2011-01-02 23:19:45 +00:00
9c69406f2b
fix a miscompilation of tramp3d-v4: when forming a memcpy, we have to make
...
sure that the loop we're promoting into a memcpy doesn't mutate the input
of the memcpy. Before we were just checking that the dest of the memcpy
wasn't mod/ref'd by the loop.
llvm-svn: 122712
2011-01-02 21:14:18 +00:00
5702a43c09
If a loop iterates exactly once (has backedge count = 0) then don't
...
mess with it. We'd rather peel/unroll it than convert all of its
stores into memsets.
llvm-svn: 122711
2011-01-02 20:24:21 +00:00
8455b6e45e
enhance loop idiom recognition to scan *all* unconditionally executed
...
blocks in a loop, instead of just the header block. This makes it more
aggressive, able to handle Duncan's Ada examples.
llvm-svn: 122704
2011-01-02 19:01:03 +00:00
0469e01c02
add a list of opportunities for future improvement.
...
llvm-svn: 122701
2011-01-02 18:32:09 +00:00
ddf58010bd
Allow loop-idiom to run on multiple BB loops, but still only scan the loop
...
header for now for memset/memcpy opportunities. It turns out that loop-rotate
is successfully rotating loops, but *DOESN'T MERGE THE BLOCKS*, turning "for
loops" into 2 basic block loops that loop-idiom was ignoring.
With this fix, we form many *many* more memcpy and memsets than before, including
on the "history" loops in the viterbi benchmark, which look like this:
for (j=0; j<MAX_history; ++j) {
history_new[i][j+1] = history[2*i][j];
}
Transforming these loops into memcpy's speeds up the viterbi benchmark from
11.98s to 3.55s on my machine. Woo.
llvm-svn: 122685
2011-01-02 07:58:36 +00:00
5b5a043d82
remove debugging code.
...
llvm-svn: 122683
2011-01-02 07:37:13 +00:00
12f91befce
add some -stats output.
...
llvm-svn: 122682
2011-01-02 07:36:44 +00:00
85b6d81d41
teach loop idiom recognition to form memcpy's from simple loops.
...
llvm-svn: 122678
2011-01-02 03:37:56 +00:00
a3514441e0
add a validity check that was missed, fixing a crash on the
...
new testcase.
llvm-svn: 122662
2011-01-01 20:12:04 +00:00
91a4435875
improve validity check to handle constant-trip-count loops more
...
aggressively. In practice, this doesn't help anything though,
see the todo.
llvm-svn: 122660
2011-01-01 19:54:22 +00:00
8b3baf6d75
implement the "no aliasing accesses in loop" safety check. This pass
...
should be correct now.
llvm-svn: 122659
2011-01-01 19:39:01 +00:00
65a699d4d0
simplify this, isBytewiseValue handles the extra check. We still
...
check for "multiple of a byte" in size to make it clear that the
>> 3 below is safe.
llvm-svn: 122604
2010-12-28 18:53:48 +00:00
5cf10e691b
Silence gcc warning about an unused variable when doing a release build.
...
llvm-svn: 122593
2010-12-28 09:41:15 +00:00
cb18bfa3d2
fix some issues Frits noticed, add AliasAnalysis as a dependency
...
llvm-svn: 122585
2010-12-27 18:39:08 +00:00
b9fe685b9a
have loop-idiom nuke instructions that feed stores that get removed.
...
llvm-svn: 122574
2010-12-27 00:03:23 +00:00
29e14edc8d
implement enough of the memset inference algorithm to recognize and insert
...
memsets. This is still missing one important validity check, but this is enough
to compile stuff like this:
void test0(std::vector<char> &X) {
for (std::vector<char>::iterator I = X.begin(), E = X.end(); I != E; ++I)
*I = 0;
}
void test1(std::vector<int> &X) {
for (long i = 0, e = X.size(); i != e; ++i)
X[i] = 0x01010101;
}
With:
$ clang t.cpp -S -o - -O2 -emit-llvm | opt -loop-idiom | opt -O3 | llc
to:
__Z5test0RSt6vectorIcSaIcEE: ## @_Z5test0RSt6vectorIcSaIcEE
## BB#0: ## %entry
subq $8, %rsp
movq (%rdi), %rax
movq 8(%rdi), %rsi
cmpq %rsi, %rax
je LBB0_2
## BB#1: ## %bb.nph
subq %rax, %rsi
movq %rax, %rdi
callq ___bzero
LBB0_2: ## %for.end
addq $8, %rsp
ret
...
__Z5test1RSt6vectorIiSaIiEE: ## @_Z5test1RSt6vectorIiSaIiEE
## BB#0: ## %entry
subq $8, %rsp
movq (%rdi), %rax
movq 8(%rdi), %rdx
subq %rax, %rdx
cmpq $4, %rdx
jb LBB1_2
## BB#1: ## %for.body.preheader
andq $-4, %rdx
movl $1, %esi
movq %rax, %rdi
callq _memset
LBB1_2: ## %for.end
addq $8, %rsp
ret
llvm-svn: 122573
2010-12-26 23:42:51 +00:00
7c5f9c35d1
sketch more of this out.
...
llvm-svn: 122567
2010-12-26 20:45:45 +00:00
81ae3f299a
actually add the file...
...
llvm-svn: 122563
2010-12-26 19:39:38 +00:00
Chris Lattner