Changes in directory llvm/lib/CodeGen/SelectionDAG:
SelectionDAGISel.cpp updated: 1.350 -> 1.351
---
Log message:
add initial support for handling inline asms with multiple constraints.
This doesn't do the "right thing" but will probably work in most cases.
This implements CodeGen/PowerPC/2007-01-29-lbrx-asm.ll.
---
Diffs of the changes: (+42 -4)
SelectionDAGISel.cpp | 46 ++++++++++++++++++++++++++++++++++++++++++----
1 files changed, 42 insertions(+), 4 deletions(-)
Index: llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
diff -u llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp:1.350
llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp:1.351
--- llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp:1.350 Mon Jan 29
16:58:52 2007
+++ llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp Mon Jan 29 17:45:14 2007
@@ -2433,6 +2433,44 @@
return RegsForValue();
}
+/// getConstraintGenerality - Return an integer indicating how general CT is.
+static unsigned getConstraintGenerality(TargetLowering::ConstraintType CT) {
+ switch (CT) {
+ default: assert(0 && "Unknown constraint type!");
+ case TargetLowering::C_Other:
+ case TargetLowering::C_Unknown:
+ return 0;
+ case TargetLowering::C_Register:
+ return 1;
+ case TargetLowering::C_RegisterClass:
+ return 2;
+ case TargetLowering::C_Memory:
+ return 3;
+ }
+}
+
+static std::string GetMostGeneralConstraint(std::vector<std::string> &C,
+ const TargetLowering &TLI) {
+ assert(!C.empty() && "Must have at least one constraint");
+ if (C.size() == 1) return C[0];
+
+ std::string *Current = &C[0];
+ // If we have multiple constraints, try to pick the most general one ahead
+ // of time. This isn't a wonderful solution, but handles common cases.
+ TargetLowering::ConstraintType Flavor = TLI.getConstraintType(Current[0][0]);
+ for (unsigned j = 1, e = C.size(); j != e; ++j) {
+ TargetLowering::ConstraintType ThisFlavor = TLI.getConstraintType(C[j][0]);
+ if (getConstraintGenerality(ThisFlavor) >
+ getConstraintGenerality(Flavor)) {
+ // This constraint letter is more general than the previous one,
+ // use it.
+ Flavor = ThisFlavor;
+ Current = &C[j];
+ }
+ }
+ return *Current;
+}
+
/// visitInlineAsm - Handle a call to an InlineAsm object.
///
@@ -2462,8 +2500,8 @@
std::set<unsigned> OutputRegs, InputRegs;
unsigned OpNum = 1;
for (unsigned i = 0, e = Constraints.size(); i != e; ++i) {
- assert(Constraints[i].Codes.size() == 1 && "Only handles one code so
far!");
- std::string &ConstraintCode = Constraints[i].Codes[0];
+ std::string ConstraintCode =
+ GetMostGeneralConstraint(Constraints[i].Codes, TLI);
MVT::ValueType OpVT;
@@ -2527,8 +2565,8 @@
OpNum = 1;
for (unsigned i = 0, e = Constraints.size(); i != e; ++i) {
- assert(Constraints[i].Codes.size() == 1 && "Only handles one code so
far!");
- std::string &ConstraintCode = Constraints[i].Codes[0];
+ std::string ConstraintCode =
+ GetMostGeneralConstraint(Constraints[i].Codes, TLI);
switch (Constraints[i].Type) {
case InlineAsm::isOutput: {
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