Displaying 7 results from an estimated 7 matches for "vmovimm".
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movimm
2010 Nov 12
0
[LLVMdev] Simple NEON optimization
...of an optimization pass? Which classes should I look first?
I recommend implementing this as a target-specific DAG combine optimization. We already have target-specific DAG nodes for the relevant NEON comparison operations (ARMISD::VCEQ, etc. -- see ARMISelLowering.h) as well as the vmov (ARMISD::VMOVIMM). You just need to teach the DAG combiner how to fold them together. Here's what you need to do (all of this code is in ARMISelLowering.cpp):
0. (You don't actually need to do anything, but I'm just mentioning it FYI.) For selection DAG nodes that are not target-specific, you need to...
2010 Nov 12
2
[LLVMdev] Simple NEON optimization
Hi folks, me again,
So, I want to implement a simple optimization in a NEON case I've seen
these days, most as a matter of exercise, but it also simplifies (just
a bit) the code generated.
The case is simple:
uint32x2_t x, res;
res = vceq_u32(x, vcreate_u32(0));
This will generate the following code:
; zero d16
vmov.i32 d16, #0x0
; load a
2010 Nov 12
2
[LLVMdev] Simple NEON optimization
...7:52, Bob Wilson <bob.wilson at apple.com> wrote:
> I recommend implementing this as a target-specific DAG combine optimization. We already have target-specific DAG nodes for the relevant NEON comparison operations (ARMISD::VCEQ, etc. -- see ARMISelLowering.h) as well as the vmov (ARMISD::VMOVIMM). You just need to teach the DAG combiner how to fold them together. Here's what you need to do (all of this code is in ARMISelLowering.cpp):
Hi Bob,
I thought so... I'll get cracked and see if I can generate some simple tests.
Thank you very much for the detailed explanation!
cheers,...
2010 Nov 12
0
[LLVMdev] Simple NEON optimization
..., Bob Wilson <bob.wilson at apple.com> wrote:
>> I recommend implementing this as a target-specific DAG combine optimization. We already have target-specific DAG nodes for the relevant NEON comparison operations (ARMISD::VCEQ, etc. -- see ARMISelLowering.h) as well as the vmov (ARMISD::VMOVIMM). You just need to teach the DAG combiner how to fold them together. Here's what you need to do (all of this code is in ARMISelLowering.cpp):
>
> Hi Bob,
>
> I thought so... I'll get cracked and see if I can generate some simple tests.
>
> Thank you very much for the...
2010 Nov 12
1
[LLVMdev] Simple NEON optimization
...b Wilson <bob.wilson at apple.com> wrote:
>>> I recommend implementing this as a target-specific DAG combine optimization. We already have target-specific DAG nodes for the relevant NEON comparison operations (ARMISD::VCEQ, etc. -- see ARMISelLowering.h) as well as the vmov (ARMISD::VMOVIMM). You just need to teach the DAG combiner how to fold them together. Here's what you need to do (all of this code is in ARMISelLowering.cpp):
>>
>> Hi Bob,
>>
>> I thought so... I'll get cracked and see if I can generate some simple tests.
>>
>> Than...
2014 Sep 19
2
[LLVMdev] More careful treatment of floating point exceptions
Hi Sanjay,
Thanks, I saw this flag and it's definitely should be considered, but
it appeared to me to be static characteristic of target platform. I'm
not sure how appropriate it would be to change its value from a front-end.
It says "Has", while optional flag would rather say "Uses" meaning that
implementation cares about floating point exceptions.
Regards,
Sergey
2014 Sep 25
2
[LLVMdev] More careful treatment of floating point exceptions
...{
if (const ConstantFP *CFP = dyn_cast<ConstantFP>(CP->getConstVal()))
return CFP->getValueAPF().isPosZero();
}
+ } else if (Op->getOpcode() == ISD::BITCAST &&
+ Op->getValueType(0) == MVT::f64) {
+ // Handle (ISD::BITCAST (ARMISD::VMOVIMM (ISD::TargetConstant 0)) MVT::f64)
+ // created by LowerConstantFP().
+ SDValue BitcastOp = Op->getOperand(0);
+ if (BitcastOp->getOpcode() == ARMISD::VMOVIMM) {
+ SDValue MoveOp = BitcastOp->getOperand(0);
+ if (MoveOp->getOpcode() == ISD::TargetConstant &&
+...