Thumb2 two-operand 'mul' instruction wide encoding parsing.

rdar://10449724

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144684 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Target/ARM/ARMInstrThumb2.td b/lib/Target/ARM/ARMInstrThumb2.td
index 03077c0f72dfad743fe2ae47d24660907af52f3c..6129fa307c40b9a286c2c7d885eaf0f1291806f3 100644 (file)
--- a/lib/Target/ARM/ARMInstrThumb2.td
+++ b/lib/Target/ARM/ARMInstrThumb2.td
@@ -4084,3 +4084,8 @@ def : t2InstAlias<"sxth${p} $Rd, $Rm$rot",
 // for isel.
 def : t2InstAlias<"mov${p} $Rd, $imm",
                   (t2MVNi rGPR:$Rd, t2_so_imm_not:$imm, pred:$p, zero_reg)>;
+
+
+// Wide 'mul' encoding can be specified with only two operands.
+def : t2InstAlias<"mul${p} $Rn, $Rm",
+                  (t2MUL rGPR:$Rn, rGPR:$Rn, rGPR:$Rm, pred:$p)>;

diff --git a/lib/Target/ARM/AsmParser/ARMAsmParser.cpp b/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
index fda1c88e72efa042fa320e0111f9e6689b7429f6..1a1c1a64a49b9da1df58b1fce211240befac68c4 100644 (file)
--- a/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
+++ b/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
@@ -4106,6 +4106,20 @@ bool ARMAsmParser::shouldOmitCCOutOperand(StringRef Mnemonic,
         static_cast<ARMOperand*>(Operands[4])->getReg())))
     return true;
 
+  // Also check the 'mul' syntax variant that doesn't specify an explicit
+  // destination register.
+  if (isThumbTwo() && Mnemonic == "mul" && Operands.size() == 5 &&
+      static_cast<ARMOperand*>(Operands[1])->getReg() == 0 &&
+      static_cast<ARMOperand*>(Operands[3])->isReg() &&
+      static_cast<ARMOperand*>(Operands[4])->isReg() &&
+      // If the registers aren't low regs  or the cc_out operand is zero
+      // outside of an IT block, we have to use the 32-bit encoding, so
+      // remove the cc_out operand.
+      (!isARMLowRegister(static_cast<ARMOperand*>(Operands[3])->getReg()) ||
+       !isARMLowRegister(static_cast<ARMOperand*>(Operands[4])->getReg()) ||
+       !inITBlock()))
+    return true;
+
 
 
   // Register-register 'add/sub' for thumb does not have a cc_out operand