6502/llvm-6502
1
0
Fork 0
mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2025-06-13 04:38:24 +00:00
Code Issues Projects Releases Wiki Activity

Pull fptrunc's upwards through selects when one of the select's selectands was a constant. This has a number of benefits, including producing small immediates (easier to materialize, smaller constant pools) as well as being more likely to allow the fptrunc to fuse with a preceding instruction (truncating selects are unusual).

Browse Source 
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191929 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Owen Anderson
2013-10-03 21:08:05 +00:00
parent e5830c4e26
commit 03e84c9df9
2 changed files with 25 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files

13
lib/Transforms/InstCombine/InstCombineCasts.cpp
View File

@ -1229,6 +1229,19 @@ Instruction *InstCombiner::visitFPTrunc(FPTruncInst &CI) {
}
}
// (fptrunc (select cond, R1, Cst)) -->
// (select cond, (fptrunc R1), (fptrunc Cst))
SelectInst *SI = dyn_cast<SelectInst>(CI.getOperand(0));
if (SI &&
(isa<ConstantFP>(SI->getOperand(1)) ||
isa<ConstantFP>(SI->getOperand(2)))) {
Value *LHSTrunc = Builder->CreateFPTrunc(SI->getOperand(1),
CI.getType());
Value *RHSTrunc = Builder->CreateFPTrunc(SI->getOperand(2),
CI.getType());
return SelectInst::Create(SI->getOperand(0), LHSTrunc, RHSTrunc);
}
IntrinsicInst *II = dyn_cast<IntrinsicInst>(CI.getOperand(0));
if (II) {
switch (II->getIntrinsicID()) {