Distinguish early clobber output operands from clobbered registers.

Both become <earlyclobber> defs on the INLINEASM MachineInstr, but we
now use two different asm operand kinds.

The new Kind_Clobber is treated identically to the old
Kind_RegDefEarlyClobber for now, but x87 floating point stack inline
assembly does care about the difference.

This will pop a register off the stack:

  asm("fstp %st" : : "t"(x) : "st");

While this will pop the input and push an output:

  asm("fst %st" : "=&t"(r) : "t"(x));

We need to know if ST0 was a clobber or an output operand, and we can't
depend on <dead> flags for that.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@133902 91177308-0d34-0410-b5e6-96231b3b80d8

5 files changed, 8 insertions, 5 deletions

diff --git a/lib/CodeGen/MachineInstr.cpp b/lib/CodeGen/MachineInstr.cpp
index d4d8202..938b83d 100644
--- a/lib/CodeGen/MachineInstr.cpp
+++ b/lib/CodeGen/MachineInstr.cpp
@@ -1443,9 +1443,10 @@ void MachineInstr::print(raw_ostream &OS, const TargetMachine *TM) const {
       switch (InlineAsm::getKind(Flag)) {
       case InlineAsm::Kind_RegUse:             OS << ":[reguse]"; break;
       case InlineAsm::Kind_RegDef:             OS << ":[regdef]"; break;
+      case InlineAsm::Kind_RegDefEarlyClobber: OS << ":[regdef-ec]"; break;
+      case InlineAsm::Kind_Clobber:            OS << ":[clobber]"; break;
       case InlineAsm::Kind_Imm:                OS << ":[imm]"; break;
       case InlineAsm::Kind_Mem:                OS << ":[mem]"; break;
-      case InlineAsm::Kind_RegDefEarlyClobber: OS << ":[regdef-ec]"; break;
       default: OS << ":[??" << InlineAsm::getKind(Flag) << ']'; break;
       }
 
diff --git a/lib/CodeGen/SelectionDAG/InstrEmitter.cpp b/lib/CodeGen/SelectionDAG/InstrEmitter.cpp
index 3c6a46e..e8c9c51 100644
--- a/lib/CodeGen/SelectionDAG/InstrEmitter.cpp
+++ b/lib/CodeGen/SelectionDAG/InstrEmitter.cpp
@@ -851,6 +851,7 @@ EmitSpecialNode(SDNode *Node, bool IsClone, bool IsCloned,
         }
         break;
       case InlineAsm::Kind_RegDefEarlyClobber:
+      case InlineAsm::Kind_Clobber:
         for (; NumVals; --NumVals, ++i) {
           unsigned Reg = cast<RegisterSDNode>(Node->getOperand(i))->getReg();
           MI->addOperand(MachineOperand::CreateReg(Reg, /*isDef=*/ true,
diff --git a/lib/CodeGen/SelectionDAG/ScheduleDAGFast.cpp b/lib/CodeGen/SelectionDAG/ScheduleDAGFast.cpp
index 7b560d1..6bed1db 100644
--- a/lib/CodeGen/SelectionDAG/ScheduleDAGFast.cpp
+++ b/lib/CodeGen/SelectionDAG/ScheduleDAGFast.cpp
@@ -490,7 +490,8 @@ bool ScheduleDAGFast::DelayForLiveRegsBottomUp(SUnit *SU,
 
         ++i; // Skip the ID value.
         if (InlineAsm::isRegDefKind(Flags) ||
-            InlineAsm::isRegDefEarlyClobberKind(Flags)) {
+            InlineAsm::isRegDefEarlyClobberKind(Flags) ||
+            InlineAsm::isClobberKind(Flags)) {
           // Check for def of register or earlyclobber register.
           for (; NumVals; --NumVals, ++i) {
             unsigned Reg = cast<RegisterSDNode>(Node->getOperand(i))->getReg();
diff --git a/lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp b/lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp
index a827187..1053b88 100644
--- a/lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp
+++ b/lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp
@@ -1092,7 +1092,8 @@ DelayForLiveRegsBottomUp(SUnit *SU, SmallVector<unsigned, 4> &LRegs) {
 
         ++i; // Skip the ID value.
         if (InlineAsm::isRegDefKind(Flags) ||
-            InlineAsm::isRegDefEarlyClobberKind(Flags)) {
+            InlineAsm::isRegDefEarlyClobberKind(Flags) ||
+            InlineAsm::isClobberKind(Flags)) {
           // Check for def of register or earlyclobber register.
           for (; NumVals; --NumVals, ++i) {
             unsigned Reg = cast<RegisterSDNode>(Node->getOperand(i))->getReg();
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
index 19bfa33..3001206 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
@@ -6051,8 +6051,7 @@ void SelectionDAGBuilder::visitInlineAsm(ImmutableCallSite CS) {
       // Add the clobbered value to the operand list, so that the register
       // allocator is aware that the physreg got clobbered.
       if (!OpInfo.AssignedRegs.Regs.empty())
-        OpInfo.AssignedRegs.AddInlineAsmOperands(
-                                            InlineAsm::Kind_RegDefEarlyClobber,
+        OpInfo.AssignedRegs.AddInlineAsmOperands(InlineAsm::Kind_Clobber,
                                                  false, 0, DAG,
                                                  AsmNodeOperands);
       break;