ASR #32 is not allowed on Thumb2 USAT and SSAT instructions.

llvm-svn: 140560

3 files changed, 37 insertions, 3 deletions

diff --git a/llvm/lib/Target/ARM/ARMInstrThumb2.td b/llvm/lib/Target/ARM/ARMInstrThumb2.td
index 44804bdbf31..e8874c7f218 100644
--- a/llvm/lib/Target/ARM/ARMInstrThumb2.td
+++ b/llvm/lib/Target/ARM/ARMInstrThumb2.td
@@ -28,6 +28,18 @@ def it_mask : Operand<i32> {
   let ParserMatchClass = it_mask_asmoperand;
 }
 
+// t2_shift_imm: An integer that encodes a shift amount and the type of shift
+// (asr or lsl). The 6-bit immediate encodes as:
+//    {5}     0 ==> lsl
+//            1     asr
+//    {4-0}   imm5 shift amount.
+//            asr #32 not allowed
+def t2_shift_imm : Operand<i32> {
+  let PrintMethod = "printShiftImmOperand";
+  let ParserMatchClass = ShifterImmAsmOperand;
+  let DecoderMethod = "DecodeT2ShifterImmOperand";
+}
+
 // Shifted operands. No register controlled shifts for Thumb2.
 // Note: We do not support rrx shifted operands yet.
 def t2_so_reg : Operand<i32>,    // reg imm
@@ -2023,7 +2035,8 @@ class T2SatI<dag oops, dag iops, InstrItinClass itin,
 }
 
 def t2SSAT: T2SatI<
-              (outs rGPR:$Rd), (ins imm1_32:$sat_imm, rGPR:$Rn, shift_imm:$sh),
+              (outs rGPR:$Rd),
+              (ins imm1_32:$sat_imm, rGPR:$Rn, t2_shift_imm:$sh),
               NoItinerary, "ssat", "\t$Rd, $sat_imm, $Rn$sh", []> {
   let Inst{31-27} = 0b11110;
   let Inst{25-22} = 0b1100;
@@ -2047,7 +2060,8 @@ def t2SSAT16: T2SatI<
 }
 
 def t2USAT: T2SatI<
-               (outs rGPR:$Rd), (ins imm0_31:$sat_imm, rGPR:$Rn, shift_imm:$sh),
+               (outs rGPR:$Rd),
+               (ins imm0_31:$sat_imm, rGPR:$Rn, t2_shift_imm:$sh),
                 NoItinerary, "usat", "\t$Rd, $sat_imm, $Rn$sh", []> {
   let Inst{31-27} = 0b11110;
   let Inst{25-22} = 0b1110;
@@ -3928,6 +3942,8 @@ def : t2InstAlias<"sxtb16${p} $Rd, $Rm",
                 (t2SXTB16 rGPR:$Rd, rGPR:$Rm, 0, pred:$p)>;
 def : t2InstAlias<"sxth${p} $Rd, $Rm",
                 (t2SXTH rGPR:$Rd, rGPR:$Rm, 0, pred:$p)>;
+def : t2InstAlias<"sxth${p} $Rd, $Rm",
+                (t2SXTH rGPR:$Rd, rGPR:$Rm, 0, pred:$p)>;
 
 def : t2InstAlias<"uxtab${p} $Rd, $Rn, $Rm",
                 (t2UXTAB rGPR:$Rd, rGPR:$Rn, rGPR:$Rm, 0, pred:$p)>;
diff --git a/llvm/lib/Target/ARM/AsmParser/ARMAsmParser.cpp b/llvm/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
index e62899e7b02..543340f8e45 100644
--- a/llvm/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
+++ b/llvm/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
@@ -2255,7 +2255,11 @@ parseShifterImm(SmallVectorImpl<MCParsedAsmOperand*> &Operands) {
       Error(E, "'asr' shift amount must be in range [1,32]");
       return MatchOperand_ParseFail;
     }
-    // asr #32 encoded as asr #0.
+    // asr #32 encoded as asr #0, but is not allowed in Thumb2 mode.
+    if (isThumb() && Val == 32) {
+      Error(E, "'asr #32' shift amount not allowed in Thumb mode");
+      return MatchOperand_ParseFail;
+    }
     if (Val == 32) Val = 0;
   } else {
     // Shift amount must be in [1,32]
diff --git a/llvm/lib/Target/ARM/Disassembler/ARMDisassembler.cpp b/llvm/lib/Target/ARM/Disassembler/ARMDisassembler.cpp
index a775cf61b55..c8d13213518 100644
--- a/llvm/lib/Target/ARM/Disassembler/ARMDisassembler.cpp
+++ b/llvm/lib/Target/ARM/Disassembler/ARMDisassembler.cpp
@@ -307,6 +307,9 @@ static DecodeStatus DecodeT2Adr(llvm::MCInst &Inst, unsigned Val,
                                 uint64_t Address, const void *Decoder);
 static DecodeStatus DecodeT2LdStPre(llvm::MCInst &Inst, unsigned Val,
                                 uint64_t Address, const void *Decoder);
+static DecodeStatus DecodeT2ShifterImmOperand(llvm::MCInst &Inst, unsigned Val,
+                                uint64_t Address, const void *Decoder);
+
 
 
 #include "ARMGenDisassemblerTables.inc"
@@ -3876,3 +3879,14 @@ static DecodeStatus DecodeT2Adr(llvm::MCInst &Inst, uint32_t Insn,
   return MCDisassembler::Success;
 }
 
+static DecodeStatus DecodeT2ShifterImmOperand(llvm::MCInst &Inst, uint32_t Val,
+                                              uint64_t Address,
+                                              const void *Decoder) {
+  DecodeStatus S = MCDisassembler::Success;
+
+  // Shift of "asr #32" is not allowed in Thumb2 mode.
+  if (Val == 0x20) S = MCDisassembler::SoftFail;
+  Inst.addOperand(MCOperand::CreateImm(Val));
+  return S;
+}
+