Move the Thumb2 SSAT and USAT optional shift operator out of the

instruction opcode.  This fixes part of PR7792.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@111047 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 21 insertions, 39 deletions

diff --git a/lib/Target/ARM/ARMInstrThumb2.td b/lib/Target/ARM/ARMInstrThumb2.td
index 67c8c95..3165af6 100644
--- a/lib/Target/ARM/ARMInstrThumb2.td
+++ b/lib/Target/ARM/ARMInstrThumb2.td
@@ -1510,24 +1510,13 @@ def t2USADA8  : T2I_mac<0, 0b111, 0b0000, (outs rGPR:$dst),
 
 // Signed/Unsigned saturate -- for disassembly only
 
-def t2SSATlsl:T2I<(outs rGPR:$dst), (ins i32imm:$bit_pos,rGPR:$a,i32imm:$shamt),
-                    NoItinerary, "ssat", "\t$dst, $bit_pos, $a, lsl $shamt",
-                    [/* For disassembly only; pattern left blank */]> {
-  let Inst{31-27} = 0b11110;
-  let Inst{25-22} = 0b1100;
-  let Inst{20} = 0;
-  let Inst{15} = 0;
-  let Inst{21} = 0;        // sh = '0'
-}
-
-def t2SSATasr:T2I<(outs rGPR:$dst), (ins i32imm:$bit_pos,rGPR:$a,i32imm:$shamt),
-                    NoItinerary, "ssat", "\t$dst, $bit_pos, $a, asr $shamt",
-                    [/* For disassembly only; pattern left blank */]> {
+def t2SSAT: T2I<(outs rGPR:$dst), (ins i32imm:$bit_pos, rGPR:$a, sat_shift:$sh),
+                NoItinerary, "ssat", "\t$dst, $bit_pos, $a$sh",
+                [/* For disassembly only; pattern left blank */]> {
   let Inst{31-27} = 0b11110;
   let Inst{25-22} = 0b1100;
   let Inst{20} = 0;
   let Inst{15} = 0;
-  let Inst{21} = 1;        // sh = '1'
 }
 
 def t2SSAT16: T2I<(outs rGPR:$dst), (ins i32imm:$bit_pos, rGPR:$a), NoItinerary,
@@ -1542,24 +1531,13 @@ def t2SSAT16: T2I<(outs rGPR:$dst), (ins i32imm:$bit_pos, rGPR:$a), NoItinerary,
   let Inst{7-6} = 0b00;    // imm2 = '00'
 }
 
-def t2USATlsl:T2I<(outs rGPR:$dst), (ins i32imm:$bit_pos,rGPR:$a,i32imm:$shamt),
-                     NoItinerary, "usat", "\t$dst, $bit_pos, $a, lsl $shamt",
-                     [/* For disassembly only; pattern left blank */]> {
-  let Inst{31-27} = 0b11110;
-  let Inst{25-22} = 0b1110;
-  let Inst{20} = 0;
-  let Inst{15} = 0;
-  let Inst{21} = 0;        // sh = '0'
-}
-
-def t2USATasr:T2I<(outs rGPR:$dst), (ins i32imm:$bit_pos,rGPR:$a,i32imm:$shamt),
-                     NoItinerary, "usat", "\t$dst, $bit_pos, $a, asr $shamt",
-                     [/* For disassembly only; pattern left blank */]> {
+def t2USAT: T2I<(outs rGPR:$dst), (ins i32imm:$bit_pos, rGPR:$a, sat_shift:$sh),
+                NoItinerary, "usat", "\t$dst, $bit_pos, $a$sh",
+                [/* For disassembly only; pattern left blank */]> {
   let Inst{31-27} = 0b11110;
   let Inst{25-22} = 0b1110;
   let Inst{20} = 0;
   let Inst{15} = 0;
-  let Inst{21} = 1;        // sh = '1'
 }
 
 def t2USAT16: T2I<(outs rGPR:$dst), (ins i32imm:$bit_pos, rGPR:$a), NoItinerary,
@@ -1574,8 +1552,8 @@ def t2USAT16: T2I<(outs rGPR:$dst), (ins i32imm:$bit_pos, rGPR:$a), NoItinerary,
   let Inst{7-6} = 0b00;    // imm2 = '00'
 }
 
-def : T2Pat<(int_arm_ssat GPR:$a, imm:$pos), (t2SSATlsl imm:$pos, GPR:$a, 0)>;
-def : T2Pat<(int_arm_usat GPR:$a, imm:$pos), (t2USATlsl imm:$pos, GPR:$a, 0)>;
+def : T2Pat<(int_arm_ssat GPR:$a, imm:$pos), (t2SSAT imm:$pos, GPR:$a, 0)>;
+def : T2Pat<(int_arm_usat GPR:$a, imm:$pos), (t2USAT imm:$pos, GPR:$a, 0)>;
 
 //===----------------------------------------------------------------------===//
 //  Shift and rotate Instructions.
diff --git a/lib/Target/ARM/Disassembler/ThumbDisassemblerCore.h b/lib/Target/ARM/Disassembler/ThumbDisassemblerCore.h
index 1a142be..701c32a 100644
--- a/lib/Target/ARM/Disassembler/ThumbDisassemblerCore.h
+++ b/lib/Target/ARM/Disassembler/ThumbDisassemblerCore.h
@@ -1462,8 +1462,8 @@ static bool DisassembleThumb2DPModImm(MCInst &MI, unsigned Opcode,
 
 static inline bool Thumb2SaturateOpcode(unsigned Opcode) {
   switch (Opcode) {
-  case ARM::t2SSATlsl: case ARM::t2SSATasr: case ARM::t2SSAT16:
-  case ARM::t2USATlsl: case ARM::t2USATasr: case ARM::t2USAT16:
+  case ARM::t2SSAT: case ARM::t2SSAT16:
+  case ARM::t2USAT: case ARM::t2USAT16:
     return true;
   default:
     return false;
@@ -1471,7 +1471,7 @@ static inline bool Thumb2SaturateOpcode(unsigned Opcode) {
 }
 
 /// DisassembleThumb2Sat - Disassemble Thumb2 saturate instructions:
-/// o t2SSAT[lsl|asr], t2USAT[lsl|asr]: Rs sat_pos Rn shamt
+/// o t2SSAT, t2USAT: Rs sat_pos Rn shamt
 /// o t2SSAT16, t2USAT16: Rs sat_pos Rn
 static bool DisassembleThumb2Sat(MCInst &MI, unsigned Opcode, uint32_t insn,
                                  unsigned &NumOpsAdded, BO B) {
@@ -1483,9 +1483,7 @@ static bool DisassembleThumb2Sat(MCInst &MI, unsigned Opcode, uint32_t insn,
                                                      decodeRs(insn))));
 
   unsigned Pos = slice(insn, 4, 0);
-  if (Opcode == ARM::t2SSATlsl ||
-      Opcode == ARM::t2SSATasr ||
-      Opcode == ARM::t2SSAT16)
+  if (Opcode == ARM::t2SSAT || Opcode == ARM::t2SSAT16)
     Pos += 1;
   MI.addOperand(MCOperand::CreateImm(Pos));
 
@@ -1493,11 +1491,17 @@ static bool DisassembleThumb2Sat(MCInst &MI, unsigned Opcode, uint32_t insn,
                                                      decodeRn(insn))));
 
   if (NumOpsAdded == 4) {
+    ARM_AM::ShiftOpc Opc = (slice(insn, 21, 21) != 0 ?
+                            ARM_AM::asr : ARM_AM::lsl);
     // Inst{14-12:7-6} encodes the imm5 shift amount.
     unsigned ShAmt = slice(insn, 14, 12) << 2 | slice(insn, 7, 6);
-    if ((Opcode == ARM::t2SSATasr || Opcode == ARM::t2USATasr) && ShAmt == 0)
-      ShAmt = 32;
-    MI.addOperand(MCOperand::CreateImm(ShAmt));
+    if (ShAmt == 0) {
+      if (Opc == ARM_AM::asr)
+        ShAmt = 32;
+      else
+        Opc = ARM_AM::no_shift;
+    }
+    MI.addOperand(MCOperand::CreateImm(ARM_AM::getSORegOpc(Opc, ShAmt)));
   }
   return true;
 }