Put int the getReg cast optimization from x86 so that we generate fewer
move instructions for the register allocator to coalesce.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@17608 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/PowerPC/PPC32ISelSimple.cpp b/lib/Target/PowerPC/PPC32ISelSimple.cpp
index 1dd946a..0e8b7b0 100644
--- a/lib/Target/PowerPC/PPC32ISelSimple.cpp
+++ b/lib/Target/PowerPC/PPC32ISelSimple.cpp
@@ -502,6 +502,10 @@
unsigned Reg = makeAnotherReg(V->getType());
copyConstantToRegister(MBB, IPt, C, Reg);
return Reg;
+ } else if (CastInst *CI = dyn_cast<CastInst>(V)) {
+ // Do not emit noop casts at all, unless it's a double -> float cast.
+ if (getClassB(CI->getType()) == getClassB(CI->getOperand(0)->getType()))
+ return getReg(CI->getOperand(0), MBB, IPt);
} else if (AllocaInst *AI = dyn_castFixedAlloca(V)) {
unsigned Reg = makeAnotherReg(V->getType());
unsigned FI = getFixedSizedAllocaFI(AI);
@@ -3129,6 +3133,10 @@
unsigned SrcClass = getClassB(Op->getType());
unsigned DestClass = getClassB(CI.getType());
+ // Noop casts are not emitted: getReg will return the source operand as the
+ // register to use for any uses of the noop cast.
+ if (DestClass == SrcClass) return;
+
// If this is a cast from a 32-bit integer to a Long type, and the only uses
// of the cast are GEP instructions, then the cast does not need to be
// generated explicitly, it will be folded into the GEP.