ARM IAS: support implicit immediate 0s for {LD,ST}R{B,}T

The ARM ARM indicates the mnemonics as follows:

  ldrbt{<c>}{<q>} <Rt>, [<Rn>], {, #+/-<imm>}
  ldrt{<c>}{<q>} <Rt>, [<Rn>] {, #+/-<imm>}
  strbt{<c>}{<q>} <Rt>, [<Rn>] {, #<imm>}
  strt{<c>}{<q>} <Rt>, [<Rn>] {, #+/-<imm>}

This improves the parser to deal with the implicit immediate 0 for the mnemonics
as per the specification.

Thanks to Joerg Sonnenberger for the tests!

llvm-svn: 198914

1 files changed, 45 insertions, 27 deletions

diff --git a/llvm/lib/Target/ARM/ARMInstrInfo.td b/llvm/lib/Target/ARM/ARMInstrInfo.td
index cbf67c96458..b80eefd398c 100644
--- a/llvm/lib/Target/ARM/ARMInstrInfo.td
+++ b/llvm/lib/Target/ARM/ARMInstrInfo.td
@@ -2444,23 +2444,28 @@ def LDRT_POST_REG : AI2ldstidx<1, 0, 0, (outs GPR:$Rt, GPR:$Rn_wb),
   let DecoderMethod = "DecodeAddrMode2IdxInstruction";
 }
 
-def LDRT_POST_IMM : AI2ldstidx<1, 0, 0, (outs GPR:$Rt, GPR:$Rn_wb),
-                    (ins addr_offset_none:$addr, am2offset_imm:$offset),
-                   IndexModePost, LdFrm, IIC_iLoad_ru,
-                   "ldrt", "\t$Rt, $addr, $offset",
-                   "$addr.base = $Rn_wb", []> {
+class LDRTImmediate<bit has_offset, string args, dag iops>
+  : AI2ldstidx<1, 0, 0, (outs GPR:$Rt, GPR:$Rn_wb), iops,
+               IndexModePost, LdFrm, IIC_iLoad_ru,
+               "ldrt", args, "$addr.base = $Rn_wb", []> {
   // {12}     isAdd
   // {11-0}   imm12/Rm
   bits<14> offset;
   bits<4> addr;
   let Inst{25} = 0;
-  let Inst{23} = offset{12};
+  let Inst{23} = !if(has_offset, offset{12}, 1);
   let Inst{21} = 1; // overwrite
   let Inst{19-16} = addr;
-  let Inst{11-0} = offset{11-0};
+  let Inst{11-0} = !if(has_offset, offset{11-0}, 0);
   let DecoderMethod = "DecodeAddrMode2IdxInstruction";
 }
 
+def LDRT_POST_IMM
+  : LDRTImmediate<1, "\t$Rt, $addr, $offset",
+                  (ins addr_offset_none:$addr, am2offset_imm:$offset)>;
+def LDRT_POST_IMM_0
+  : LDRTImmediate<0, "\t$Rt, $addr", (ins addr_offset_none:$addr)>;
+
 def LDRBT_POST_REG : AI2ldstidx<1, 1, 0, (outs GPR:$Rt, GPR:$Rn_wb),
                      (ins addr_offset_none:$addr, am2offset_reg:$offset),
                      IndexModePost, LdFrm, IIC_iLoad_bh_ru,
@@ -2480,23 +2485,28 @@ def LDRBT_POST_REG : AI2ldstidx<1, 1, 0, (outs GPR:$Rt, GPR:$Rn_wb),
   let DecoderMethod = "DecodeAddrMode2IdxInstruction";
 }
 
-def LDRBT_POST_IMM : AI2ldstidx<1, 1, 0, (outs GPR:$Rt, GPR:$Rn_wb),
-                     (ins addr_offset_none:$addr, am2offset_imm:$offset),
+class LDRBTImmediate<bit has_offset, string args, dag iops>
+  : AI2ldstidx<1, 1, 0, (outs GPR:$Rt, GPR:$Rn_wb), iops,
                     IndexModePost, LdFrm, IIC_iLoad_bh_ru,
-                    "ldrbt", "\t$Rt, $addr, $offset",
-                    "$addr.base = $Rn_wb", []> {
+                    "ldrbt", args, "$addr.base = $Rn_wb", []> {
   // {12}     isAdd
   // {11-0}   imm12/Rm
   bits<14> offset;
   bits<4> addr;
   let Inst{25} = 0;
-  let Inst{23} = offset{12};
+  let Inst{23} = !if(has_offset, offset{12}, 1);
   let Inst{21} = 1; // overwrite
   let Inst{19-16} = addr;
-  let Inst{11-0} = offset{11-0};
+  let Inst{11-0} = !if(has_offset, offset{11-0}, 0);
   let DecoderMethod = "DecodeAddrMode2IdxInstruction";
 }
 
+def LDRBT_POST_IMM
+  : LDRBTImmediate<1, "\t$Rt, $addr, $offset",
+                   (ins addr_offset_none:$addr, am2offset_imm:$offset)>;
+def LDRBT_POST_IMM_0
+  : LDRBTImmediate<0, "\t$Rt, $addr", (ins addr_offset_none:$addr)>;
+
 multiclass AI3ldrT<bits<4> op, string opc> {
   def i : AI3ldstidxT<op, 1, (outs GPR:$Rt, GPR:$base_wb),
                       (ins addr_offset_none:$addr, postidx_imm8:$offset),
@@ -2748,23 +2758,27 @@ def STRBT_POST_REG : AI2ldstidx<0, 1, 0, (outs GPR:$Rn_wb),
   let DecoderMethod = "DecodeAddrMode2IdxInstruction";
 }
 
-def STRBT_POST_IMM : AI2ldstidx<0, 1, 0, (outs GPR:$Rn_wb),
-                   (ins GPR:$Rt, addr_offset_none:$addr, am2offset_imm:$offset),
-                   IndexModePost, StFrm, IIC_iStore_bh_ru,
-                   "strbt", "\t$Rt, $addr, $offset",
-                   "$addr.base = $Rn_wb", []> {
+class STRBTImmediate<bit has_offset, string args, dag iops>
+  : AI2ldstidx<0, 1, 0, (outs GPR:$Rn_wb), iops, IndexModePost, StFrm,
+               IIC_iStore_bh_ru, "strbt", args, "$addr.base = $Rn_wb", []> {
   // {12}     isAdd
   // {11-0}   imm12/Rm
   bits<14> offset;
   bits<4> addr;
   let Inst{25} = 0;
-  let Inst{23} = offset{12};
+  let Inst{23} = !if(has_offset, offset{12}, 1);
   let Inst{21} = 1; // overwrite
   let Inst{19-16} = addr;
-  let Inst{11-0} = offset{11-0};
+  let Inst{11-0} = !if(has_offset, offset{11-0}, 0);
   let DecoderMethod = "DecodeAddrMode2IdxInstruction";
 }
 
+def STRBT_POST_IMM
+  : STRBTImmediate<1, "\t$Rt, $addr, $offset",
+                   (ins GPR:$Rt, addr_offset_none:$addr, am2offset_imm:$offset)>;
+def STRBT_POST_IMM_0
+  : STRBTImmediate<0, "\t$Rt, $addr", (ins GPR:$Rt, addr_offset_none:$addr)>;
+
 let mayStore = 1, neverHasSideEffects = 1 in {
 def STRT_POST_REG : AI2ldstidx<0, 0, 0, (outs GPR:$Rn_wb),
                    (ins GPR:$Rt, addr_offset_none:$addr, am2offset_reg:$offset),
@@ -2785,22 +2799,26 @@ def STRT_POST_REG : AI2ldstidx<0, 0, 0, (outs GPR:$Rn_wb),
   let DecoderMethod = "DecodeAddrMode2IdxInstruction";
 }
 
-def STRT_POST_IMM : AI2ldstidx<0, 0, 0, (outs GPR:$Rn_wb),
-                   (ins GPR:$Rt, addr_offset_none:$addr, am2offset_imm:$offset),
-                   IndexModePost, StFrm, IIC_iStore_ru,
-                   "strt", "\t$Rt, $addr, $offset",
-                   "$addr.base = $Rn_wb", []> {
+class STRTImmediate<bit has_offset, string args, dag iops>
+  : AI2ldstidx<0, 0, 0, (outs GPR:$Rn_wb), iops, IndexModePost, StFrm,
+               IIC_iStore_ru, "strt", args, "$addr.base = $Rn_wb", []> {
   // {12}     isAdd
   // {11-0}   imm12/Rm
   bits<14> offset;
   bits<4> addr;
   let Inst{25} = 0;
-  let Inst{23} = offset{12};
+  let Inst{23} = !if(has_offset, offset{12}, 1);
   let Inst{21} = 1; // overwrite
   let Inst{19-16} = addr;
-  let Inst{11-0} = offset{11-0};
+  let Inst{11-0} = !if(has_offset, offset{11-0}, 0);
   let DecoderMethod = "DecodeAddrMode2IdxInstruction";
 }
+
+def STRT_POST_IMM
+  : STRTImmediate<1, "\t$Rt, $addr, $offset",
+                  (ins GPR:$Rt, addr_offset_none:$addr, am2offset_imm:$offset)>;
+def STRT_POST_IMM_0
+  : STRTImmediate<0, "\t$Rt, $addr", (ins GPR:$Rt, addr_offset_none:$addr)>;
 }