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
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
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
- Added a new format for instructions where the source register is implied
and it is same as the destination register. Used for pseudo instructions
that clear the destination register.
llvm-svn: 25872
XMM registers. There are many known deficiencies and fixmes, which will be
addressed ASAP. The major benefit of this work is that it will allow the
LLVM register allocator to allocate FP registers across basic blocks.
The x86 backend will still default to x87 style FP. To enable this work,
you must pass -enable-sse-scalar-fp and either -sse2 or -sse3 to llc.
An example before and after would be for:
double foo(double *P) { double Sum = 0; int i; for (i = 0; i < 1000; ++i)
Sum += P[i]; return Sum; }
The inner loop looks like the following:
x87:
.LBB_foo_1: # no_exit
fldl (%esp)
faddl (%eax,%ecx,8)
fstpl (%esp)
incl %ecx
cmpl $1000, %ecx
#FP_REG_KILL
jne .LBB_foo_1 # no_exit
SSE2:
addsd (%eax,%ecx,8), %xmm0
incl %ecx
cmpl $1000, %ecx
#FP_REG_KILL
jne .LBB_foo_1 # no_exit
llvm-svn: 22340
I/O port instructions on x86. The specific code sequence is tailored to
the parameters and return value of the intrinsic call.
Added the ability for implicit defintions to be printed in the Instruction
Printer.
Added the ability for RawFrm instruction to print implict uses and
defintions with correct comma output. This required adjustment to some
methods so that a leading comma would or would not be printed.
llvm-svn: 12782
the size of the immediate and the memory operand on instructions that
use them. This resolves problems with instructions that take both a
memory and an immediate operand but their sizes differ (i.e. ADDmi32b).
llvm-svn: 11967
SingleSource except oopack and Oscar. (Sorry, Oscar.)
include/llvm/Target/TargetInstrInfo.h: Remove virtual print method. Add
accessors for ImplicitUses/Defs.
lib/Target/TargetInstrInfo.cpp: Remove virtual print method. If you
really wanted this, just use MI->print(O, TM); instead...
lib/Target/X86:
FloatingPoint.cpp: ...like this.
X86InstrInfo.h: Remove virtual print method. Define the PrintImplUses
target-specific flag bit.
X86InstrInfo.def: Add the PrintImplUses flag to all the instructions
which implicitly use CL, because the assembler needs to see the CL in
order to generate the right instruction.
Printer.cpp: Ditch fnIndex at Chris's request. Now we use CurrentFnName
to name constants in the constant pool for each function instead. This
avoids keeping state between runOnMachineFunction() invocations, which
is a no-no. Having MangledGlobals be global is a bogon I'd like to get
rid of too, but making it a static member of Printer causes link errors
(why???).
Make NumberForBB into a member of Printer instead of a global, too.
Make printOp and printMemReference into methods of Printer.
X86InstrInfo::print is now Printer::printMachineInstruction, because
TargetInstrInfo::print is history. (Because of this, we have to qualify
the names of some TargetInstrInfo methods we call.)
Print out the ImplicitUses field of any instruction we print that has
the PrintImplUses bit set.
llvm-svn: 6924
" <SIZE> PTR " string when emitting assembly.
Target/X86/X86InstrInfo.def: Tidy up a bit:
Squashed everything down to 118 chars wide, wrapping lines so that
comment is at the same point on each line. Rename "NoImpRegs" as
"NoIR". (most instructions have NoImpRegs twice on a line, so this
saves 10 columns).
Also, annotate various instructions with flags for size of memory operand.
(MemArg16, MemArg32, MemArg64, etc.)
Target/X86/X86InstrInfo.h: Define flags for size of memory operand.
(MemArg16, MemArg32, MemArg64, etc.)
llvm-svn: 4932
Bill Wendling