[ARM] Clean up choice of narrow instructions in ARMAsmParser, NFC

This patch makes a couple of changes to how we decide whether to use the narrow
or wide encoding of thumb2 instructions:
 * Common out the detection of the .w qualifier
 * Check for the CPSR operand in a consistent way

Differential Revision: https://reviews.llvm.org/D34460

llvm-svn: 305992

1 files changed, 27 insertions, 33 deletions

diff --git a/llvm/lib/Target/ARM/AsmParser/ARMAsmParser.cpp b/llvm/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
index 19fba3033bb..51e0118469b 100644
--- a/llvm/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
+++ b/llvm/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
@@ -6860,6 +6860,17 @@ static unsigned getRealVLDOpcode(unsigned Opc, unsigned &Spacing) {
 bool ARMAsmParser::processInstruction(MCInst &Inst,
                                       const OperandVector &Operands,
                                       MCStreamer &Out) {
+  // Check if we have the wide qualifier, because if it's present we
+  // must avoid selecting a 16-bit thumb instruction.
+  bool HasWideQualifier = false;
+  for (auto &Op : Operands) {
+    ARMOperand &ARMOp = static_cast<ARMOperand&>(*Op);
+    if (ARMOp.isToken() && ARMOp.getToken() == ".w") {
+      HasWideQualifier = true;
+      break;
+    }
+  }
+
   switch (Inst.getOpcode()) {
   // Alias for alternate form of 'ldr{,b}t Rt, [Rn], #imm' instruction.
   case ARM::LDRT_POST:
@@ -6939,8 +6950,7 @@ bool ARMAsmParser::processInstruction(MCInst &Inst,
     // Select the narrow version if the immediate will fit.
     if (Inst.getOperand(1).getImm() > 0 &&
         Inst.getOperand(1).getImm() <= 0xff &&
-        !(static_cast<ARMOperand &>(*Operands[2]).isToken() &&
-          static_cast<ARMOperand &>(*Operands[2]).getToken() == ".w"))
+        !HasWideQualifier)
       Inst.setOpcode(ARM::tLDRpci);
     else
       Inst.setOpcode(ARM::t2LDRpci);
@@ -6971,10 +6981,9 @@ bool ARMAsmParser::processInstruction(MCInst &Inst,
     else if (Inst.getOpcode() == ARM::t2LDRConstPool)
       TmpInst.setOpcode(ARM::t2LDRpci);
     const ARMOperand &PoolOperand =
-      (static_cast<ARMOperand &>(*Operands[2]).isToken() &&
-       static_cast<ARMOperand &>(*Operands[2]).getToken() == ".w") ?
-      static_cast<ARMOperand &>(*Operands[4]) :
-      static_cast<ARMOperand &>(*Operands[3]);
+      (HasWideQualifier ?
+       static_cast<ARMOperand &>(*Operands[4]) :
+       static_cast<ARMOperand &>(*Operands[3]));
     const MCExpr *SubExprVal = PoolOperand.getConstantPoolImm();
     // If SubExprVal is a constant we may be able to use a MOV
     if (isa<MCConstantExpr>(SubExprVal) &&
@@ -8117,8 +8126,7 @@ bool ARMAsmParser::processInstruction(MCInst &Inst,
     if (isARMLowRegister(Inst.getOperand(0).getReg()) &&
         isARMLowRegister(Inst.getOperand(1).getReg()) &&
         Inst.getOperand(5).getReg() == (inITBlock() ? 0 : ARM::CPSR) &&
-        !(static_cast<ARMOperand &>(*Operands[3]).isToken() &&
-          static_cast<ARMOperand &>(*Operands[3]).getToken() == ".w")) {
+        !HasWideQualifier) {
       unsigned NewOpc;
       switch (Inst.getOpcode()) {
       default: llvm_unreachable("unexpected opcode");
@@ -8415,10 +8423,8 @@ bool ARMAsmParser::processInstruction(MCInst &Inst,
         !isARMLowRegister(Inst.getOperand(0).getReg()) ||
         (Inst.getOperand(2).isImm() &&
          (unsigned)Inst.getOperand(2).getImm() > 255) ||
-        ((!inITBlock() && Inst.getOperand(5).getReg() != ARM::CPSR) ||
-         (inITBlock() && Inst.getOperand(5).getReg() != 0)) ||
-        (static_cast<ARMOperand &>(*Operands[3]).isToken() &&
-         static_cast<ARMOperand &>(*Operands[3]).getToken() == ".w"))
+        Inst.getOperand(5).getReg() != (inITBlock() ? 0 : ARM::CPSR) ||
+        HasWideQualifier)
       break;
     MCInst TmpInst;
     TmpInst.setOpcode(Inst.getOpcode() == ARM::t2ADDri ?
@@ -8447,8 +8453,7 @@ bool ARMAsmParser::processInstruction(MCInst &Inst,
     }
     if (!Transform ||
         Inst.getOperand(5).getReg() != 0 ||
-        (static_cast<ARMOperand &>(*Operands[3]).isToken() &&
-         static_cast<ARMOperand &>(*Operands[3]).getToken() == ".w"))
+        HasWideQualifier)
       break;
     MCInst TmpInst;
     TmpInst.setOpcode(ARM::tADDhirr);
@@ -8568,11 +8573,8 @@ bool ARMAsmParser::processInstruction(MCInst &Inst,
     if (isARMLowRegister(Inst.getOperand(0).getReg()) &&
         (Inst.getOperand(1).isImm() &&
          (unsigned)Inst.getOperand(1).getImm() <= 255) &&
-        ((!inITBlock() && Inst.getOperand(2).getImm() == ARMCC::AL &&
-          Inst.getOperand(4).getReg() == ARM::CPSR) ||
-         (inITBlock() && Inst.getOperand(4).getReg() == 0)) &&
-        (!static_cast<ARMOperand &>(*Operands[2]).isToken() ||
-         static_cast<ARMOperand &>(*Operands[2]).getToken() != ".w")) {
+        Inst.getOperand(4).getReg() == (inITBlock() ? 0 : ARM::CPSR) &&
+        !HasWideQualifier) {
       // The operands aren't in the same order for tMOVi8...
       MCInst TmpInst;
       TmpInst.setOpcode(ARM::tMOVi8);
@@ -8593,8 +8595,7 @@ bool ARMAsmParser::processInstruction(MCInst &Inst,
         isARMLowRegister(Inst.getOperand(1).getReg()) &&
         Inst.getOperand(2).getImm() == ARMCC::AL &&
         Inst.getOperand(4).getReg() == ARM::CPSR &&
-        (!static_cast<ARMOperand &>(*Operands[2]).isToken() ||
-         static_cast<ARMOperand &>(*Operands[2]).getToken() != ".w")) {
+        !HasWideQualifier) {
       // The operands aren't the same for tMOV[S]r... (no cc_out)
       MCInst TmpInst;
       TmpInst.setOpcode(Inst.getOperand(4).getReg() ? ARM::tMOVSr : ARM::tMOVr);
@@ -8616,8 +8617,7 @@ bool ARMAsmParser::processInstruction(MCInst &Inst,
     if (isARMLowRegister(Inst.getOperand(0).getReg()) &&
         isARMLowRegister(Inst.getOperand(1).getReg()) &&
         Inst.getOperand(2).getImm() == 0 &&
-        (!static_cast<ARMOperand &>(*Operands[2]).isToken() ||
-         static_cast<ARMOperand &>(*Operands[2]).getToken() != ".w")) {
+        !HasWideQualifier) {
       unsigned NewOpc;
       switch (Inst.getOpcode()) {
       default: llvm_unreachable("Illegal opcode!");
@@ -8716,11 +8716,8 @@ bool ARMAsmParser::processInstruction(MCInst &Inst,
     if ((isARMLowRegister(Inst.getOperand(1).getReg()) &&
          isARMLowRegister(Inst.getOperand(2).getReg())) &&
         Inst.getOperand(0).getReg() == Inst.getOperand(1).getReg() &&
-        ((!inITBlock() && Inst.getOperand(5).getReg() == ARM::CPSR) ||
-         (inITBlock() && Inst.getOperand(5).getReg() != ARM::CPSR)) &&
-        (!static_cast<ARMOperand &>(*Operands[3]).isToken() ||
-         !static_cast<ARMOperand &>(*Operands[3]).getToken().equals_lower(
-             ".w"))) {
+        Inst.getOperand(5).getReg() == (inITBlock() ? 0 : ARM::CPSR) &&
+        !HasWideQualifier) {
       unsigned NewOpc;
       switch (Inst.getOpcode()) {
         default: llvm_unreachable("unexpected opcode");
@@ -8756,11 +8753,8 @@ bool ARMAsmParser::processInstruction(MCInst &Inst,
          isARMLowRegister(Inst.getOperand(2).getReg())) &&
         (Inst.getOperand(0).getReg() == Inst.getOperand(1).getReg() ||
          Inst.getOperand(0).getReg() == Inst.getOperand(2).getReg()) &&
-        ((!inITBlock() && Inst.getOperand(5).getReg() == ARM::CPSR) ||
-         (inITBlock() && Inst.getOperand(5).getReg() != ARM::CPSR)) &&
-        (!static_cast<ARMOperand &>(*Operands[3]).isToken() ||
-         !static_cast<ARMOperand &>(*Operands[3]).getToken().equals_lower(
-             ".w"))) {
+        Inst.getOperand(5).getReg() == (inITBlock() ? 0 : ARM::CPSR) &&
+        !HasWideQualifier) {
       unsigned NewOpc;
       switch (Inst.getOpcode()) {
         default: llvm_unreachable("unexpected opcode");