into:

_t:
        movl 8(%esp), %ecx
        movl 4(%esp), %eax
        cmpl %ecx, %eax
        je LBB1_3       #bb17
LBB1_1: #bb
        cmpl %ecx, %eax
        jg LBB1_4       #cond_true
LBB1_2: #cond_false
        subl %eax, %ecx
        cmpl %ecx, %eax
        jne LBB1_1      #bb
LBB1_3: #bb17
        ret
LBB1_4: #cond_true
        subl %ecx, %eax
        cmpl %ecx, %eax
        jne LBB1_1      #bb
        jmp LBB1_3      #bb17

instead of:

_t:
        subl $4, %esp
        movl %esi, (%esp)
        movl 12(%esp), %ecx
        movl 8(%esp), %eax
        cmpl %ecx, %eax
        je LBB1_4       #bb17
LBB1_1: #bb.outer
        movl %ecx, %edx
        negl %edx
LBB1_2: #bb
        cmpl %ecx, %eax
        jle LBB1_5      #cond_false
LBB1_3: #cond_true
        addl %edx, %eax
        cmpl %ecx, %eax
        jne LBB1_2      #bb
LBB1_4: #bb17
        movl (%esp), %esi
        addl $4, %esp
        ret
LBB1_5: #cond_false
        movl %ecx, %edx
        subl %eax, %edx
        movl %eax, %esi
        addl %esi, %esi
        cmpl %ecx, %esi
        je LBB1_4       #bb17
LBB1_6: #cond_false.bb.outer_crit_edge
        movl %edx, %ecx
        jmp LBB1_1      #bb.outer

llvm-svn: 37252

Test case at Transformations/SCCP/2007-05-16-InvokeCrash.ll

llvm-svn: 37185

llvm-svn: 37057

llvm-svn: 37034

llvm-svn: 36996

llvm-svn: 36994

with unknown trip counts. This is left off by default, and a
command-line option enables it. It also begins to separate loop
unrolling into a utility routine; eventually it might be made usable
from other passes.

It currently works by inserting conditional branches between each
unrolled iteration, unless it proves that the trip count is a
multiple of a constant integer > 1, which it currently only does in
the rare case that the trip count expression is a Mul operator with
a ConstantInt operand. Eventually this information might be provided
by other sources, for example by a pass that peels/splits the loop
for this purpose.

llvm-svn: 36990

Transforms/InstCombine/2006-12-08-ICmp-Combining.ll

llvm-svn: 36989

llvm-svn: 36984

Testcases :
http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20070507/049451.html
http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20070507/049452.html

llvm-svn: 36955

llvm-svn: 36936

llvm-svn: 36935

llvm-svn: 36917

llvm-svn: 36873

llvm-svn: 36857

llvm-svn: 36809

llvm-svn: 36807

If we have a LCSSA, only modify the input value if the inval was defined
by an instruction in the loop.  If defined by something before the loop,
it is still valid.

llvm-svn: 36784

llvm-svn: 36782

llvm-svn: 36775

slightly nicer than using CallInst with an extra check; thanks Chris.

llvm-svn: 36743

address operand in a prefetch intrinsic.

llvm-svn: 36713

llvm-svn: 36662

Due to darwin gcc bug, one version of darwin linker coalesces
static const int, which defauts PassID based pass identification.

llvm-svn: 36652

llvm-svn: 36632

llvm-svn: 36527

previous clients.  This fixes MallocBench/gs

llvm-svn: 36525

llvm-svn: 36523

llvm-svn: 36521

for unrelated casts.

llvm-svn: 36511

llvm-svn: 36475

llvm-svn: 36444

llvm-svn: 36441

copies from a constant global, then we can change the reads to read from the
global instead of from the alloca.  This eliminates the alloca and the memcpy,
and promotes secondary optimizations (because the loads are now loads from
a constant global).

This is important for a common C idiom:

void foo() {
   int A[] = {1,2,3,4,5,6,7,8,9...};
   ... only reads of A ...
}

For some reason, people forget to mark the array static or const.

This triggers on these multisource benchmarks:
JM/ldecode: block_pos, [3 x [4 x [4 x i32]]]
FreeBench/mason: m, [18 x i32], inlined 4 times
MiBench/office-stringsearch: search_strings, [1332 x i8*]
MiBench/office-stringsearch: find_strings, [1333 x i8*]
Prolangs-C++/city: dirs, [9 x i8*], inlined 4 places

and these spec benchmarks:
177.mesa: message, [8 x [32 x i8]]
186.crafty: bias_rl45, [64 x i32]
186.crafty: diag_sq, [64 x i32]
186.crafty: empty, [9 x i8]
186.crafty: xlate, [15 x i8]
186.crafty: status, [13 x i8]
186.crafty: bdinfo, [25 x i8]
445.gobmk: routines, [16 x i8*]
458.sjeng: piece_rep, [14 x i8*]
458.sjeng: t, [13 x i32], inlined 4 places.
464.h264ref: block8x8_idx, [3 x [4 x [4 x i32]]]
464.h264ref: block_pos, [3 x [4 x [4 x i32]]]
464.h264ref: j_off_tab, [12 x i32]

This implements Transforms/ScalarRepl/memcpy-from-global.ll

llvm-svn: 36429

llvm-svn: 36426

this approach is no longer appropriate.

llvm-svn: 36421

http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20070423/048376.html

llvm-svn: 36417

my approach to this, so hopefully I'll find a way to do this without making this slower.

llvm-svn: 36392

http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20070423/048333.html

llvm-svn: 36380

llvm-svn: 36300