Add support for the PowerPC-specific inline asm Z constraint and y modifier.
The Z constraint specifies an r+r memory address, and the y modifier expands
to the "r, r" in the asm string. For this initial implementation, the base
register is forced to r0 (which has the special meaning of 0 for r+r addressing
on PowerPC) and the full address is taken in the second register. In the
future, this should be improved.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@167388 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/PowerPC/PPCAsmPrinter.cpp b/lib/Target/PowerPC/PPCAsmPrinter.cpp
index 72395bb..4387730 100644
--- a/lib/Target/PowerPC/PPCAsmPrinter.cpp
+++ b/lib/Target/PowerPC/PPCAsmPrinter.cpp
@@ -284,8 +284,22 @@
unsigned AsmVariant,
const char *ExtraCode,
raw_ostream &O) {
- if (ExtraCode && ExtraCode[0])
- return true; // Unknown modifier.
+ if (ExtraCode && ExtraCode[0]) {
+ if (ExtraCode[1] != 0) return true; // Unknown modifier.
+
+ switch (ExtraCode[0]) {
+ default: return true; // Unknown modifier.
+ case 'y': // A memory reference for an X-form instruction
+ {
+ const char *RegName = "r0";
+ if (!Subtarget.isDarwin()) RegName = stripRegisterPrefix(RegName);
+ O << RegName << ", ";
+ printOperand(MI, OpNo, O);
+ return false;
+ }
+ }
+ }
+
assert(MI->getOperand(OpNo).isReg());
O << "0(";
printOperand(MI, OpNo, O);
diff --git a/lib/Target/PowerPC/PPCISelLowering.cpp b/lib/Target/PowerPC/PPCISelLowering.cpp
index 0922011..cda7e8c 100644
--- a/lib/Target/PowerPC/PPCISelLowering.cpp
+++ b/lib/Target/PowerPC/PPCISelLowering.cpp
@@ -6443,6 +6443,14 @@
case 'v':
case 'y':
return C_RegisterClass;
+ case 'Z':
+ // FIXME: While Z does indicate a memory constraint, it specifically
+ // indicates an r+r address (used in conjunction with the 'y' modifier
+ // in the replacement string). Currently, we're forcing the base
+ // register to be r0 in the asm printer (which is interpreted as zero)
+ // and forming the complete address in the second register. This is
+ // suboptimal.
+ return C_Memory;
}
}
return TargetLowering::getConstraintType(Constraint);
@@ -6485,6 +6493,9 @@
case 'y':
weight = CW_Register;
break;
+ case 'Z':
+ weight = CW_Memory;
+ break;
}
return weight;
}