[llvm-commits] [llvm] r146831 - /llvm/trunk/lib/Target/X86/X86ISelLowering.cpp
Benjamin Kramer
benny.kra at googlemail.com
Sat Dec 17 06:36:06 PST 2011
Author: d0k
Date: Sat Dec 17 08:36:05 2011
New Revision: 146831
URL: http://llvm.org/viewvc/llvm-project?rev=146831&view=rev
Log:
X86: Factor the bswap asm matching to be slightly less horrible to read.
Modified:
llvm/trunk/lib/Target/X86/X86ISelLowering.cpp
Modified: llvm/trunk/lib/Target/X86/X86ISelLowering.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/X86ISelLowering.cpp?rev=146831&r1=146830&r2=146831&view=diff
==============================================================================
--- llvm/trunk/lib/Target/X86/X86ISelLowering.cpp (original)
+++ llvm/trunk/lib/Target/X86/X86ISelLowering.cpp Sat Dec 17 08:36:05 2011
@@ -14700,11 +14700,41 @@
// 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 {
InlineAsm *IA = cast<InlineAsm>(CI->getCalledValue());
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"
SmallVector<StringRef, 4> AsmPieces;
SplitString(AsmStr, AsmPieces, ";\n");
@@ -14712,35 +14742,27 @@
switch (AsmPieces.size()) {
default: return false;
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,
- // we will turn this bswap into something that will be lowered to logical ops
- // instead of emitting the bswap asm. For now, we don't support 486 or lower
- // so don't worry about this.
+ // we will turn this bswap into something that will be lowered to logical
+ // ops instead of emitting the bswap asm. For now, we don't support 486 or
+ // lower so don't worry about this.
// bswap $0
- if (AsmPieces.size() == 2 &&
- (AsmPieces[0] == "bswap" ||
- AsmPieces[0] == "bswapq" ||
- AsmPieces[0] == "bswapl") &&
- (AsmPieces[1] == "$0" ||
- AsmPieces[1] == "${0:q}")) {
+ if (matchAsm(AsmPieces[0], "bswap", "$0", NULL) ||
+ matchAsm(AsmPieces[0], "bswapl", "$0", NULL) ||
+ matchAsm(AsmPieces[0], "bswapq", "$0", NULL) ||
+ matchAsm(AsmPieces[0], "bswap", "${0:q}", NULL) ||
+ matchAsm(AsmPieces[0], "bswapl", "${0:q}", NULL) ||
+ matchAsm(AsmPieces[0], "bswapq", "${0:q}", NULL)) {
// No need to check constraints, nothing other than the equivalent of
// "=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);
}
+
// rorw $$8, ${0:w} --> llvm.bswap.i16
if (CI->getType()->isIntegerTy(16) &&
- AsmPieces.size() == 3 &&
- (AsmPieces[0] == "rorw" || AsmPieces[0] == "rolw") &&
- AsmPieces[1] == "$$8," &&
- AsmPieces[2] == "${0:w}" &&
- IA->getConstraintString().compare(0, 5, "=r,0,") == 0) {
+ IA->getConstraintString().compare(0, 5, "=r,0,") == 0 &&
+ (matchAsm(AsmPieces[0], "rorw", "$$8,", "${0:w}", NULL) ||
+ matchAsm(AsmPieces[0], "rolw", "$$8,", "${0:w}", NULL))) {
AsmPieces.clear();
const std::string &ConstraintsStr = IA->getConstraintString();
SplitString(StringRef(ConstraintsStr).substr(5), AsmPieces, ",");
@@ -14749,46 +14771,26 @@
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);
- }
+ AsmPieces[3] == "~{fpsr}")
+ return IntrinsicLowering::LowerToByteSwap(CI);
}
break;
case 3:
if (CI->getType()->isIntegerTy(32) &&
- IA->getConstraintString().compare(0, 5, "=r,0,") == 0) {
- SmallVector<StringRef, 4> Words;
- SplitString(AsmPieces[0], Words, " \t,");
- if (Words.size() == 3 && Words[0] == "rorw" && Words[1] == "$$8" &&
- Words[2] == "${0:w}") {
- Words.clear();
- SplitString(AsmPieces[1], Words, " \t,");
- if (Words.size() == 3 && Words[0] == "rorl" && Words[1] == "$$16" &&
- Words[2] == "$0") {
- Words.clear();
- SplitString(AsmPieces[2], Words, " \t,");
- if (Words.size() == 3 && Words[0] == "rorw" && Words[1] == "$$8" &&
- Words[2] == "${0:w}") {
- AsmPieces.clear();
- const std::string &ConstraintsStr = IA->getConstraintString();
- SplitString(StringRef(ConstraintsStr).substr(5), AsmPieces, ",");
- std::sort(AsmPieces.begin(), AsmPieces.end());
- if (AsmPieces.size() == 4 &&
- AsmPieces[0] == "~{cc}" &&
- AsmPieces[1] == "~{dirflag}" &&
- AsmPieces[2] == "~{flags}" &&
- AsmPieces[3] == "~{fpsr}") {
- IntegerType *Ty = dyn_cast<IntegerType>(CI->getType());
- if (!Ty || Ty->getBitWidth() % 16 != 0)
- return false;
- return IntrinsicLowering::LowerToByteSwap(CI);
- }
- }
- }
- }
+ IA->getConstraintString().compare(0, 5, "=r,0,") == 0 &&
+ matchAsm(AsmPieces[0], "rorw", "$$8,", "${0:w}", NULL) &&
+ matchAsm(AsmPieces[1], "rorl", "$$16,", "$0", NULL) &&
+ matchAsm(AsmPieces[2], "rorw", "$$8,", "${0:w}", NULL)) {
+ AsmPieces.clear();
+ 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}")
+ return IntrinsicLowering::LowerToByteSwap(CI);
}
if (CI->getType()->isIntegerTy(64)) {
@@ -14797,23 +14799,10 @@
Constraints[0].Codes.size() == 1 && Constraints[0].Codes[0] == "A" &&
Constraints[1].Codes.size() == 1 && Constraints[1].Codes[0] == "0") {
// bswap %eax / bswap %edx / xchgl %eax, %edx -> llvm.bswap.i64
- SmallVector<StringRef, 4> Words;
- SplitString(AsmPieces[0], Words, " \t");
- if (Words.size() == 2 && Words[0] == "bswap" && Words[1] == "%eax") {
- Words.clear();
- 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);
- }
- }
- }
+ if (matchAsm(AsmPieces[0], "bswap", "%eax", NULL) &&
+ matchAsm(AsmPieces[1], "bswap", "%edx", NULL) &&
+ matchAsm(AsmPieces[2], "xchgl", "%eax,", "%edx", NULL))
+ return IntrinsicLowering::LowerToByteSwap(CI);
}
}
break;
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