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X86: Factor the bswap asm matching to be slightly less horrible to read. 

llvm-svn: 146831
This commit is contained in:
Benjamin Kramer 2011-12-17 14:36:05 +00:00
parent 7bfba2f0d3
commit 792edd3c75
1 changed files with 63 additions and 74 deletions
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137
llvm/lib/Target/X86/X86ISelLowering.cpp
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@ -14700,11 +14700,41 @@ bool X86TargetLowering::IsDesirableToPromoteOp(SDValue Op, EVT &PVT) const {
// X86 Inline Assembly Support // X86 Inline Assembly Support
//===----------------------------------------------------------------------===// //===----------------------------------------------------------------------===//
// Helper to match a string separated by whitespace.
static bool END_WITH_NULL matchAsm(StringRef s, ...) {
va_list ap;
va_start(ap, s);
s = s.substr(s.find_first_not_of(" \t")); // Skip leading whitespace.
while (const char *p = va_arg(ap, const char *)) {
StringRef piece(p);
if (!s.startswith(piece)) { // Check if the piece matches.
va_end(ap);
return false;
}
s = s.substr(piece.size());
StringRef::size_type i = s.find_first_not_of(" \t");
if (i == 0) { // We matched a prefix.
va_end(ap);
return false;
}
s = s.substr(i);
}
va_end(ap);
return s.empty();
}
bool X86TargetLowering::ExpandInlineAsm(CallInst *CI) const { bool X86TargetLowering::ExpandInlineAsm(CallInst *CI) const {
InlineAsm *IA = cast<InlineAsm>(CI->getCalledValue()); InlineAsm *IA = cast<InlineAsm>(CI->getCalledValue());
std::string AsmStr = IA->getAsmString(); std::string AsmStr = IA->getAsmString();
IntegerType *Ty = dyn_cast<IntegerType>(CI->getType());
if (!Ty || Ty->getBitWidth() % 16 != 0)
return false;
// TODO: should remove alternatives from the asmstring: "foo {a|b}" -> "foo a" // TODO: should remove alternatives from the asmstring: "foo {a|b}" -> "foo a"
SmallVector<StringRef, 4> AsmPieces; SmallVector<StringRef, 4> AsmPieces;
SplitString(AsmStr, AsmPieces, ";\n"); SplitString(AsmStr, AsmPieces, ";\n");
@ -14712,35 +14742,27 @@ bool X86TargetLowering::ExpandInlineAsm(CallInst *CI) const {
switch (AsmPieces.size()) { switch (AsmPieces.size()) {
default: return false; default: return false;
case 1: case 1:
AsmStr = AsmPieces[0];
AsmPieces.clear();
SplitString(AsmStr, AsmPieces, " \t"); // Split with whitespace.
// FIXME: this should verify that we are targeting a 486 or better. If not, // FIXME: this should verify that we are targeting a 486 or better. If not,
// we will turn this bswap into something that will be lowered to logical ops // we will turn this bswap into something that will be lowered to logical
// instead of emitting the bswap asm. For now, we don't support 486 or lower // ops instead of emitting the bswap asm. For now, we don't support 486 or
// so don't worry about this. // lower so don't worry about this.
// bswap $0 // bswap $0
if (AsmPieces.size() == 2 && if (matchAsm(AsmPieces[0], "bswap", "$0", NULL) ||
(AsmPieces[0] == "bswap" || matchAsm(AsmPieces[0], "bswapl", "$0", NULL) ||
AsmPieces[0] == "bswapq" || matchAsm(AsmPieces[0], "bswapq", "$0", NULL) ||
AsmPieces[0] == "bswapl") && matchAsm(AsmPieces[0], "bswap", "${0:q}", NULL) ||
(AsmPieces[1] == "$0" || matchAsm(AsmPieces[0], "bswapl", "${0:q}", NULL) ||
AsmPieces[1] == "${0:q}")) { matchAsm(AsmPieces[0], "bswapq", "${0:q}", NULL)) {
// No need to check constraints, nothing other than the equivalent of // No need to check constraints, nothing other than the equivalent of
// "=r,0" would be valid here. // "=r,0" would be valid here.
IntegerType *Ty = dyn_cast<IntegerType>(CI->getType());
if (!Ty || Ty->getBitWidth() % 16 != 0)
return false;
return IntrinsicLowering::LowerToByteSwap(CI); return IntrinsicLowering::LowerToByteSwap(CI);
} }
// rorw $$8, ${0:w} --> llvm.bswap.i16 // rorw $$8, ${0:w} --> llvm.bswap.i16
if (CI->getType()->isIntegerTy(16) && if (CI->getType()->isIntegerTy(16) &&
AsmPieces.size() == 3 && IA->getConstraintString().compare(0, 5, "=r,0,") == 0 &&
(AsmPieces[0] == "rorw" || AsmPieces[0] == "rolw") && (matchAsm(AsmPieces[0], "rorw", "$$8,", "${0:w}", NULL) ||
AsmPieces[1] == "$$8," && matchAsm(AsmPieces[0], "rolw", "$$8,", "${0:w}", NULL))) {
AsmPieces[2] == "${0:w}" &&
IA->getConstraintString().compare(0, 5, "=r,0,") == 0) {
AsmPieces.clear(); AsmPieces.clear();
const std::string &ConstraintsStr = IA->getConstraintString(); const std::string &ConstraintsStr = IA->getConstraintString();
SplitString(StringRef(ConstraintsStr).substr(5), AsmPieces, ","); SplitString(StringRef(ConstraintsStr).substr(5), AsmPieces, ",");
@ -14749,46 +14771,26 @@ bool X86TargetLowering::ExpandInlineAsm(CallInst *CI) const {
AsmPieces[0] == "~{cc}" && AsmPieces[0] == "~{cc}" &&
AsmPieces[1] == "~{dirflag}" && AsmPieces[1] == "~{dirflag}" &&
AsmPieces[2] == "~{flags}" && AsmPieces[2] == "~{flags}" &&
AsmPieces[3] == "~{fpsr}") { AsmPieces[3] == "~{fpsr}")
IntegerType *Ty = dyn_cast<IntegerType>(CI->getType()); return IntrinsicLowering::LowerToByteSwap(CI);
if (!Ty || Ty->getBitWidth() % 16 != 0)
return false;
return IntrinsicLowering::LowerToByteSwap(CI);
}
} }
break; break;
case 3: case 3:
if (CI->getType()->isIntegerTy(32) && if (CI->getType()->isIntegerTy(32) &&
IA->getConstraintString().compare(0, 5, "=r,0,") == 0) { IA->getConstraintString().compare(0, 5, "=r,0,") == 0 &&
SmallVector<StringRef, 4> Words; matchAsm(AsmPieces[0], "rorw", "$$8,", "${0:w}", NULL) &&
SplitString(AsmPieces[0], Words, " \t,"); matchAsm(AsmPieces[1], "rorl", "$$16,", "$0", NULL) &&
if (Words.size() == 3 && Words[0] == "rorw" && Words[1] == "$$8" && matchAsm(AsmPieces[2], "rorw", "$$8,", "${0:w}", NULL)) {
Words[2] == "${0:w}") { AsmPieces.clear();
Words.clear(); const std::string &ConstraintsStr = IA->getConstraintString();
SplitString(AsmPieces[1], Words, " \t,"); SplitString(StringRef(ConstraintsStr).substr(5), AsmPieces, ",");
if (Words.size() == 3 && Words[0] == "rorl" && Words[1] == "$$16" && std::sort(AsmPieces.begin(), AsmPieces.end());
Words[2] == "$0") { if (AsmPieces.size() == 4 &&
Words.clear(); AsmPieces[0] == "~{cc}" &&
SplitString(AsmPieces[2], Words, " \t,"); AsmPieces[1] == "~{dirflag}" &&
if (Words.size() == 3 && Words[0] == "rorw" && Words[1] == "$$8" && AsmPieces[2] == "~{flags}" &&
Words[2] == "${0:w}") { AsmPieces[3] == "~{fpsr}")
AsmPieces.clear(); return IntrinsicLowering::LowerToByteSwap(CI);
const std::string &ConstraintsStr = IA->getConstraintString();
SplitString(StringRef(ConstraintsStr).substr(5), AsmPieces, ",");
std::sort(AsmPieces.begin(), AsmPieces.end());
if (AsmPieces.size() == 4 &&
AsmPieces[0] == "~{cc}" &&
AsmPieces[1] == "~{dirflag}" &&
AsmPieces[2] == "~{flags}" &&
AsmPieces[3] == "~{fpsr}") {
IntegerType *Ty = dyn_cast<IntegerType>(CI->getType());
if (!Ty || Ty->getBitWidth() % 16 != 0)
return false;
return IntrinsicLowering::LowerToByteSwap(CI);
}
}
}
}
} }
if (CI->getType()->isIntegerTy(64)) { if (CI->getType()->isIntegerTy(64)) {
@ -14797,23 +14799,10 @@ bool X86TargetLowering::ExpandInlineAsm(CallInst *CI) const {
Constraints[0].Codes.size() == 1 && Constraints[0].Codes[0] == "A" && Constraints[0].Codes.size() == 1 && Constraints[0].Codes[0] == "A" &&
Constraints[1].Codes.size() == 1 && Constraints[1].Codes[0] == "0") { Constraints[1].Codes.size() == 1 && Constraints[1].Codes[0] == "0") {
// bswap %eax / bswap %edx / xchgl %eax, %edx -> llvm.bswap.i64 // bswap %eax / bswap %edx / xchgl %eax, %edx -> llvm.bswap.i64
SmallVector<StringRef, 4> Words; if (matchAsm(AsmPieces[0], "bswap", "%eax", NULL) &&
SplitString(AsmPieces[0], Words, " \t"); matchAsm(AsmPieces[1], "bswap", "%edx", NULL) &&
if (Words.size() == 2 && Words[0] == "bswap" && Words[1] == "%eax") { matchAsm(AsmPieces[2], "xchgl", "%eax,", "%edx", NULL))
Words.clear(); return IntrinsicLowering::LowerToByteSwap(CI);
SplitString(AsmPieces[1], Words, " \t");
if (Words.size() == 2 && Words[0] == "bswap" && Words[1] == "%edx") {
Words.clear();
SplitString(AsmPieces[2], Words, " \t,");
if (Words.size() == 3 && Words[0] == "xchgl" && Words[1] == "%eax" &&
Words[2] == "%edx") {
IntegerType *Ty = dyn_cast<IntegerType>(CI->getType());
if (!Ty || Ty->getBitWidth() % 16 != 0)
return false;
return IntrinsicLowering::LowerToByteSwap(CI);
}
}
}
} }
} }
break; break;