[llvm] r295732 - [ARM] Correct SP/PC handling in t2MOVr

[John Brawn via llvm-commits]

Author: john.brawn
Date: Tue Feb 21 10:41:29 2017
New Revision: 295732

URL: http://llvm.org/viewvc/llvm-project?rev=295732&view=rev
Log:
[ARM] Correct SP/PC handling in t2MOVr

PC isn't allowed in the source operand of t2MOVr, so change the register class
to one without PC. SP handling is slightly trickier and changes depending on if
we're in ARMv8, so do that in checkTargetMatchPredicate.

Differential Revision: https://reviews.llvm.org/D30199

Modified:
    llvm/trunk/lib/Target/ARM/ARMInstrThumb2.td
    llvm/trunk/lib/Target/ARM/AsmParser/ARMAsmParser.cpp

Modified: llvm/trunk/lib/Target/ARM/ARMInstrThumb2.td
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/ARM/ARMInstrThumb2.td?rev=295732&r1=295731&r2=295732&view=diff
==============================================================================
--- llvm/trunk/lib/Target/ARM/ARMInstrThumb2.td (original)
+++ llvm/trunk/lib/Target/ARM/ARMInstrThumb2.td Tue Feb 21 10:41:29 2017
@@ -1828,7 +1828,7 @@ defm t2STM : thumb2_st_mult<"stm", IIC_i
 //
 
 let hasSideEffects = 0 in
-def t2MOVr : T2sTwoReg<(outs GPRnopc:$Rd), (ins GPR:$Rm), IIC_iMOVr,
+def t2MOVr : T2sTwoReg<(outs GPRnopc:$Rd), (ins GPRnopc:$Rm), IIC_iMOVr,
                    "mov", ".w\t$Rd, $Rm", []>, Sched<[WriteALU]> {
   let Inst{31-27} = 0b11101;
   let Inst{26-25} = 0b01;
@@ -1837,11 +1837,11 @@ def t2MOVr : T2sTwoReg<(outs GPRnopc:$Rd
   let Inst{14-12} = 0b000;
   let Inst{7-4} = 0b0000;
 }
-def : t2InstAlias<"mov${p}.w $Rd, $Rm", (t2MOVr GPRnopc:$Rd, GPR:$Rm,
+def : t2InstAlias<"mov${p}.w $Rd, $Rm", (t2MOVr GPRnopc:$Rd, GPRnopc:$Rm,
                                                 pred:$p, zero_reg)>;
-def : t2InstAlias<"movs${p}.w $Rd, $Rm", (t2MOVr GPRnopc:$Rd, GPR:$Rm,
+def : t2InstAlias<"movs${p}.w $Rd, $Rm", (t2MOVr GPRnopc:$Rd, GPRnopc:$Rm,
                                                  pred:$p, CPSR)>;
-def : t2InstAlias<"movs${p} $Rd, $Rm", (t2MOVr GPRnopc:$Rd, GPR:$Rm,
+def : t2InstAlias<"movs${p} $Rd, $Rm", (t2MOVr GPRnopc:$Rd, GPRnopc:$Rm,
                                                pred:$p, CPSR)>;
 
 // AddedComplexity to ensure isel tries t2MOVi before t2MOVi16.

Modified: llvm/trunk/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/ARM/AsmParser/ARMAsmParser.cpp?rev=295732&r1=295731&r2=295732&view=diff
==============================================================================
--- llvm/trunk/lib/Target/ARM/AsmParser/ARMAsmParser.cpp (original)
+++ llvm/trunk/lib/Target/ARM/AsmParser/ARMAsmParser.cpp Tue Feb 21 10:41:29 2017
@@ -8932,6 +8932,22 @@ unsigned ARMAsmParser::checkTargetMatchP
       return Match_RequiresV6;
   }
 
+  // Before ARMv8 the rules for when SP is allowed in t2MOVr are more complex
+  // than the loop below can handle, so it uses the GPRnopc register class and
+  // we do SP handling here.
+  if (Opc == ARM::t2MOVr && !hasV8Ops())
+  {
+    // SP as both source and destination is not allowed
+    if (Inst.getOperand(0).getReg() == ARM::SP &&
+        Inst.getOperand(1).getReg() == ARM::SP)
+      return Match_RequiresV8;
+    // When flags-setting SP as either source or destination is not allowed
+    if (Inst.getOperand(4).getReg() == ARM::CPSR &&
+        (Inst.getOperand(0).getReg() == ARM::SP ||
+         Inst.getOperand(1).getReg() == ARM::SP))
+      return Match_RequiresV8;
+  }
+
   for (unsigned I = 0; I < MCID.NumOperands; ++I)
     if (MCID.OpInfo[I].RegClass == ARM::rGPRRegClassID) {
       // rGPRRegClass excludes PC, and also excluded SP before ARMv8