Where previously LLVM might emit code like this:
ucomisd %xmm1, %xmm0
setne %al
setp %cl
orb %al, %cl
jne .LBB4_2
it now emits this:
ucomisd %xmm1, %xmm0
jne .LBB4_2
jp .LBB4_2
It has fewer instructions and uses fewer registers, but it does
have more branches. And in the case that this code is followed by
a non-fallthrough edge, it may be followed by a jmp instruction,
resulting in three branch instructions in sequence. Some effort
is made to avoid this situation.
To achieve this, X86ISelLowering.cpp now recognizes FCMP_OEQ and
FCMP_UNE in lowered form, and replace them with code that emits
two branches, except in the case where it would require converting
a fall-through edge to an explicit branch.
Also, X86InstrInfo.cpp's branch analysis and transform code now
knows now to handle blocks with multiple conditional branches. It
uses loops instead of having fixed checks for up to two
instructions. It can now analyze and transform code generated
from FCMP_OEQ and FCMP_UNE.
llvm-svn: 57873
was inserted or not. This allows bitcast in fast isel to properly handle the case
where an appropriate reg-to-reg copy is not available.
llvm-svn: 55375
MachineMemOperands. The pools are owned by MachineFunctions.
This drastically reduces the number of calls to malloc/free made
during the "Emit" phase of scheduling, as well as later phases
in CodeGen. Combined with other changes, this speeds up the
"instruction selection" phase of CodeGen by 10% in some cases.
llvm-svn: 53212
Change insert/extract subreg instructions to be able to be used in TableGen patterns.
Use the above features to reimplement an x86-64 pseudo instruction as a pattern.
llvm-svn: 48130
both work right according to the new flags.
This removes the TII::isReallySideEffectFree predicate, and adds
TII::isInvariantLoad.
It removes NeverHasSideEffects+MayHaveSideEffects and adds
UnmodeledSideEffects as machine instr flags. Now the clients
can decide everything they need.
I think isRematerializable can be implemented in terms of the
flags we have now, though I will let others tackle that.
llvm-svn: 45843
a header file from libcodegen. This violates a layering order: codegen
depends on target, not the other way around. The fix to this is to
split TII into two classes, TII and TargetInstrInfoImpl, which defines
stuff that depends on libcodegen. It is defined in libcodegen, where
the base is not.
llvm-svn: 45475
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
Dan Gohman