function, then go ahead and hoist it out of the loop. This is the result:

$ cat a.c
volatile int G;

int A(int N) {
  for (; N > 0; --N)
    G++;
}
$ llc -o - -relocation-model=pic
_A:
...
LBB1_2: # bb
        movl    L_G$non_lazy_ptr-"L1$pb"(%eax), %esi
        incl    (%esi)
        incl    %edx
        cmpl    %ecx, %edx
        jne     LBB1_2  # bb
...
$ llc -o - -relocation-model=pic -machine-licm
_A:
...
        movl    L_G$non_lazy_ptr-"L1$pb"(%eax), %eax
LBB1_2: # bb
        incl    (%eax)
        incl    %edx
        cmpl    %ecx, %edx
        jne     LBB1_2  # bb
...

I'm limiting this to the MOV32rm x86 instruction for now.

llvm-svn: 45444

llvm-svn: 45418

based what flag to set on whether it was already marked as
"isRematerializable". If there was a further check to determine if it's "really"
rematerializable, then I marked it as "mayHaveSideEffects" and created a check
in the X86 back-end similar to the remat one.

llvm-svn: 45132

llvm-svn: 44727

  isTriviallyReMaterializable -> hasNoSideEffects
  isReallyTriviallyReMaterializable -> isTriviallyReMaterializable

llvm-svn: 44702

enabled by passing -tailcallopt to llc.  The optimization is
performed if the following conditions are satisfied:
* caller/callee are fastcc
* elf/pic is disabled OR
  elf/pic enabled + callee is in module + callee has
  visibility protected or hidden

llvm-svn: 42870

llvm-svn: 42783

llvm-svn: 42761

to its inverse.
Testing this as llcbeta

llvm-svn: 42661

llvm-svn: 42655

cause performance degradation.

llvm-svn: 42653

leal 1(%ecx), %edi, which requires 67H prefix.

llvm-svn: 42647

llvm-svn: 42642

llvm-svn: 42630

llvm-svn: 42459

Added support for new condition code modeling scheme (i.e. physical register dependency). These are a bunch of instructions that are duplicated so the x86 backend can support both the old and new schemes at the same time. They will be deleted after
all the kinks are worked out.

llvm-svn: 42285

can terminate a block with no fall-through.

llvm-svn: 42029

llvm-svn: 41975

llvm-svn: 41962

Patch by Sterling Stein!

llvm-svn: 41758

leal    (,%rcx,8), %rcx
It should be
leal    (,%rcx,8), %ecx

llvm-svn: 41735

Add 2-addr to 3-addr promotion code that allows 32-bit LEA to be used via subregisters when 16-bit LEA is disabled.

llvm-svn: 41007

llvm-svn: 40537

llvm-svn: 37960

their names are changed.

llvm-svn: 37876

model to include f32 variants.  Some factoring
improvments forthcoming.

llvm-svn: 37847

instruction flag, and use the flag along with a virtual member function
hook for targets to override if there are instructions that are only
trivially rematerializable with specific operands (i.e. constant pool
loads).

llvm-svn: 37728

with a general target hook to identify rematerializable instructions. Some
instructions are only rematerializable with specific operands, such as loads
from constant pools, while others are always rematerializable. This hook
allows both to be identified as being rematerializable with the same
mechanism.

llvm-svn: 37644

llvm-svn: 37578

implementation for x86.

llvm-svn: 37576

llvm-svn: 37571

llvm-svn: 37528

llvm-svn: 37266

llvm-svn: 37193

llvm-svn: 36430

llvm-svn: 36404

llvm-svn: 35638

llvm-svn: 35616

_test3:
        leaq (,%rdi,4), %rax
        orq %rdi, %rax
        ret

instead of:
_test2:
        movq %rdi, %rax
        shlq $2, %rax
        orq %rdi, %rax
        ret

llvm-svn: 35434

system assembler not groking legal instructions like "leal (,%esi,8), %ecx".

llvm-svn: 35393