ARM: Correct printing of pre-indexed operands.

According to the ARM reference manual, constant offsets are mandatory for pre-indexed addressing modes.
The MC disassembler was not obeying this when the offset is 0.
It was producing instructions like: str r0, [r1]!.
Correct syntax is: str r0, [r1, #0]!.

This change modifies the dumping of operands so that the offset is always printed, regardless of its value, when pre-indexed addressing mode is used.

Patch by Mihail Popa <Mihail.Popa@arm.com>


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@179398 91177308-0d34-0410-b5e6-96231b3b80d8

6 files changed, 100 insertions, 27 deletions

diff --git a/lib/Target/ARM/ARMInstrInfo.td b/lib/Target/ARM/ARMInstrInfo.td
index 93c18ae295..988beb6a57 100644
--- a/lib/Target/ARM/ARMInstrInfo.td
+++ b/lib/Target/ARM/ARMInstrInfo.td
@@ -744,18 +744,26 @@ def imm1_16 : Operand<i32>, PatLeaf<(imm), [{ return Imm > 0 && Imm <= 16; }],
 // addrmode_imm12 := reg +/- imm12
 //
 def MemImm12OffsetAsmOperand : AsmOperandClass { let Name = "MemImm12Offset"; }
-def addrmode_imm12 : Operand<i32>,
+class AddrMode_Imm12 : Operand<i32>,
                      ComplexPattern<i32, 2, "SelectAddrModeImm12", []> {
   // 12-bit immediate operand. Note that instructions using this encode
   // #0 and #-0 differently. We flag #-0 as the magic value INT32_MIN. All other
   // immediate values are as normal.
 
   let EncoderMethod = "getAddrModeImm12OpValue";
-  let PrintMethod = "printAddrModeImm12Operand";
   let DecoderMethod = "DecodeAddrModeImm12Operand";
   let ParserMatchClass = MemImm12OffsetAsmOperand;
   let MIOperandInfo = (ops GPR:$base, i32imm:$offsimm);
 }
+
+def addrmode_imm12 : AddrMode_Imm12 {
+  let PrintMethod = "printAddrModeImm12Operand<false>";
+}
+
+def addrmode_imm12_pre : AddrMode_Imm12 {
+  let PrintMethod = "printAddrModeImm12Operand<true>";
+}
+
 // ldst_so_reg := reg +/- reg shop imm
 //
 def MemRegOffsetAsmOperand : AsmOperandClass { let Name = "MemRegOffset"; }
@@ -855,14 +863,23 @@ def am2offset_imm : Operand<i32>,
 //
 // FIXME: split into imm vs. reg versions.
 def AddrMode3AsmOperand : AsmOperandClass { let Name = "AddrMode3"; }
-def addrmode3 : Operand<i32>,
-                ComplexPattern<i32, 3, "SelectAddrMode3", []> {
+class AddrMode3 : Operand<i32>,
+                  ComplexPattern<i32, 3, "SelectAddrMode3", []> {
   let EncoderMethod = "getAddrMode3OpValue";
-  let PrintMethod = "printAddrMode3Operand";
   let ParserMatchClass = AddrMode3AsmOperand;
   let MIOperandInfo = (ops GPR:$base, GPR:$offsreg, i32imm:$offsimm);
 }
 
+def addrmode3 : AddrMode3
+{
+  let PrintMethod = "printAddrMode3Operand<false>";
+}
+
+def addrmode3_pre : AddrMode3
+{
+  let PrintMethod = "printAddrMode3Operand<true>";
+}
+
 // FIXME: split into imm vs. reg versions.
 // FIXME: parser method to handle +/- register.
 def AM3OffsetAsmOperand : AsmOperandClass {
@@ -888,15 +905,22 @@ def ldstm_mode : OptionalDefOperand<OtherVT, (ops i32), (ops (i32 1))> {
 // addrmode5 := reg +/- imm8*4
 //
 def AddrMode5AsmOperand : AsmOperandClass { let Name = "AddrMode5"; }
-def addrmode5 : Operand<i32>,
-                ComplexPattern<i32, 2, "SelectAddrMode5", []> {
-  let PrintMethod = "printAddrMode5Operand";
+class AddrMode5 : Operand<i32>,
+                  ComplexPattern<i32, 2, "SelectAddrMode5", []> {
   let EncoderMethod = "getAddrMode5OpValue";
   let DecoderMethod = "DecodeAddrMode5Operand";
   let ParserMatchClass = AddrMode5AsmOperand;
   let MIOperandInfo = (ops GPR:$base, i32imm);
 }
 
+def addrmode5 : AddrMode5 {
+   let PrintMethod = "printAddrMode5Operand<false>";
+}
+
+def addrmode5_pre : AddrMode5 {
+   let PrintMethod = "printAddrMode5Operand<true>";
+}
+
 // addrmode6 := reg with optional alignment
 //
 def AddrMode6AsmOperand : AsmOperandClass { let Name = "AlignedMemory"; }
@@ -2241,7 +2265,7 @@ def LDRD : AI3ld<0b1101, 0, (outs GPR:$Rd, GPR:$dst2),
 multiclass AI2_ldridx<bit isByte, string opc,
                       InstrItinClass iii, InstrItinClass iir> {
   def _PRE_IMM  : AI2ldstidx<1, isByte, 1, (outs GPR:$Rt, GPR:$Rn_wb),
-                      (ins addrmode_imm12:$addr), IndexModePre, LdFrm, iii,
+                      (ins addrmode_imm12_pre:$addr), IndexModePre, LdFrm, iii,
                       opc, "\t$Rt, $addr!", "$addr.base = $Rn_wb", []> {
     bits<17> addr;
     let Inst{25} = 0;
@@ -2310,7 +2334,7 @@ defm LDRB : AI2_ldridx<1, "ldrb", IIC_iLoad_bh_iu, IIC_iLoad_bh_ru>;
 
 multiclass AI3_ldridx<bits<4> op, string opc, InstrItinClass itin> {
   def _PRE  : AI3ldstidx<op, 1, 1, (outs GPR:$Rt, GPR:$Rn_wb),
-                        (ins addrmode3:$addr), IndexModePre,
+                        (ins addrmode3_pre:$addr), IndexModePre,
                         LdMiscFrm, itin,
                         opc, "\t$Rt, $addr!", "$addr.base = $Rn_wb", []> {
     bits<14> addr;
@@ -2344,7 +2368,7 @@ defm LDRSH : AI3_ldridx<0b1111, "ldrsh", IIC_iLoad_bh_ru>;
 defm LDRSB : AI3_ldridx<0b1101, "ldrsb", IIC_iLoad_bh_ru>;
 let hasExtraDefRegAllocReq = 1 in {
 def LDRD_PRE : AI3ldstidx<0b1101, 0, 1, (outs GPR:$Rt, GPR:$Rt2, GPR:$Rn_wb),
-                          (ins addrmode3:$addr), IndexModePre,
+                          (ins addrmode3_pre:$addr), IndexModePre,
                           LdMiscFrm, IIC_iLoad_d_ru,
                           "ldrd", "\t$Rt, $Rt2, $addr!",
                           "$addr.base = $Rn_wb", []> {
@@ -2500,7 +2524,7 @@ def STRD : AI3str<0b1111, (outs), (ins GPR:$Rt, GPR:$src2, addrmode3:$addr),
 multiclass AI2_stridx<bit isByte, string opc,
                       InstrItinClass iii, InstrItinClass iir> {
   def _PRE_IMM : AI2ldstidx<0, isByte, 1, (outs GPR:$Rn_wb),
-                            (ins GPR:$Rt, addrmode_imm12:$addr), IndexModePre,
+                            (ins GPR:$Rt, addrmode_imm12_pre:$addr), IndexModePre,
                             StFrm, iii,
                             opc, "\t$Rt, $addr!", "$addr.base = $Rn_wb", []> {
     bits<17> addr;
@@ -2622,7 +2646,7 @@ def STRH_preidx: ARMPseudoInst<(outs GPR:$Rn_wb),
 
 
 def STRH_PRE  : AI3ldstidx<0b1011, 0, 1, (outs GPR:$Rn_wb),
-                           (ins GPR:$Rt, addrmode3:$addr), IndexModePre,
+                           (ins GPR:$Rt, addrmode3_pre:$addr), IndexModePre,
                            StMiscFrm, IIC_iStore_bh_ru,
                            "strh", "\t$Rt, $addr!", "$addr.base = $Rn_wb", []> {
   bits<14> addr;
@@ -2654,7 +2678,7 @@ def STRH_POST : AI3ldstidx<0b1011, 0, 0, (outs GPR:$Rn_wb),
 
 let mayStore = 1, neverHasSideEffects = 1, hasExtraSrcRegAllocReq = 1 in {
 def STRD_PRE : AI3ldstidx<0b1111, 0, 1, (outs GPR:$Rn_wb),
-                          (ins GPR:$Rt, GPR:$Rt2, addrmode3:$addr),
+                          (ins GPR:$Rt, GPR:$Rt2, addrmode3_pre:$addr),
                           IndexModePre, StMiscFrm, IIC_iStore_d_ru,
                           "strd", "\t$Rt, $Rt2, $addr!",
                           "$addr.base = $Rn_wb", []> {
@@ -4429,7 +4453,7 @@ multiclass LdStCop<bit load, bit Dbit, string asm> {
     let Inst{7-0} = addr{7-0};
     let DecoderMethod = "DecodeCopMemInstruction";
   }
-  def _PRE : ACI<(outs), (ins p_imm:$cop, c_imm:$CRd, addrmode5:$addr),
+  def _PRE : ACI<(outs), (ins p_imm:$cop, c_imm:$CRd, addrmode5_pre:$addr),
                  asm, "\t$cop, $CRd, $addr!", IndexModePre> {
     bits<13> addr;
     bits<4> cop;
@@ -4500,7 +4524,7 @@ multiclass LdSt2Cop<bit load, bit Dbit, string asm> {
     let Inst{7-0} = addr{7-0};
     let DecoderMethod = "DecodeCopMemInstruction";
   }
-  def _PRE : ACInoP<(outs), (ins p_imm:$cop, c_imm:$CRd, addrmode5:$addr),
+  def _PRE : ACInoP<(outs), (ins p_imm:$cop, c_imm:$CRd, addrmode5_pre:$addr),
                     asm, "\t$cop, $CRd, $addr!", IndexModePre> {
     bits<13> addr;
     bits<4> cop;
diff --git a/lib/Target/ARM/ARMInstrThumb2.td b/lib/Target/ARM/ARMInstrThumb2.td
index 4db37ca051..ad57de54c1 100644
--- a/lib/Target/ARM/ARMInstrThumb2.td
+++ b/lib/Target/ARM/ARMInstrThumb2.td
@@ -150,7 +150,7 @@ def lo5AllOne : PatLeaf<(i32 imm), [{
 def t2addrmode_imm12_asmoperand : AsmOperandClass {let Name="MemUImm12Offset";}
 def t2addrmode_imm12 : Operand<i32>,
                        ComplexPattern<i32, 2, "SelectT2AddrModeImm12", []> {
-  let PrintMethod = "printAddrModeImm12Operand";
+  let PrintMethod = "printAddrModeImm12Operand<false>";
   let EncoderMethod = "getAddrModeImm12OpValue";
   let DecoderMethod = "DecodeT2AddrModeImm12";
   let ParserMatchClass = t2addrmode_imm12_asmoperand;
diff --git a/lib/Target/ARM/InstPrinter/ARMInstPrinter.cpp b/lib/Target/ARM/InstPrinter/ARMInstPrinter.cpp
index 2afb20d668..3bcd083a35 100644
--- a/lib/Target/ARM/InstPrinter/ARMInstPrinter.cpp
+++ b/lib/Target/ARM/InstPrinter/ARMInstPrinter.cpp
@@ -490,7 +490,8 @@ void ARMInstPrinter::printAM3PostIndexOp(const MCInst *MI, unsigned Op,
 }
 
 void ARMInstPrinter::printAM3PreOrOffsetIndexOp(const MCInst *MI, unsigned Op,
-                                                raw_ostream &O) {
+                                                raw_ostream &O,
+                                                bool AlwaysPrintImm0) {
   const MCOperand &MO1 = MI->getOperand(Op);
   const MCOperand &MO2 = MI->getOperand(Op+1);
   const MCOperand &MO3 = MI->getOperand(Op+2);
@@ -509,7 +510,7 @@ void ARMInstPrinter::printAM3PreOrOffsetIndexOp(const MCInst *MI, unsigned Op,
   unsigned ImmOffs = ARM_AM::getAM3Offset(MO3.getImm());
   ARM_AM::AddrOpc op = ARM_AM::getAM3Op(MO3.getImm());
 
-  if (ImmOffs || (op == ARM_AM::sub)) {
+  if (AlwaysPrintImm0 || ImmOffs || (op == ARM_AM::sub)) {
     O << ", "
       << markup("<imm:")
       << "#"
@@ -520,6 +521,7 @@ void ARMInstPrinter::printAM3PreOrOffsetIndexOp(const MCInst *MI, unsigned Op,
   O << ']' << markup(">");
 }
 
+template <bool AlwaysPrintImm0>
 void ARMInstPrinter::printAddrMode3Operand(const MCInst *MI, unsigned Op,
                                            raw_ostream &O) {
   const MCOperand &MO1 = MI->getOperand(Op);
@@ -535,7 +537,7 @@ void ARMInstPrinter::printAddrMode3Operand(const MCInst *MI, unsigned Op,
     printAM3PostIndexOp(MI, Op, O);
     return;
   }
-  printAM3PreOrOffsetIndexOp(MI, Op, O);
+  printAM3PreOrOffsetIndexOp(MI, Op, O, AlwaysPrintImm0);
 }
 
 void ARMInstPrinter::printAddrMode3OffsetOperand(const MCInst *MI,
@@ -593,6 +595,7 @@ void ARMInstPrinter::printLdStmModeOperand(const MCInst *MI, unsigned OpNum,
   O << ARM_AM::getAMSubModeStr(Mode);
 }
 
+template <bool AlwaysPrintImm0>
 void ARMInstPrinter::printAddrMode5Operand(const MCInst *MI, unsigned OpNum,
                                            raw_ostream &O) {
   const MCOperand &MO1 = MI->getOperand(OpNum);
@@ -608,7 +611,7 @@ void ARMInstPrinter::printAddrMode5Operand(const MCInst *MI, unsigned OpNum,
 
   unsigned ImmOffs = ARM_AM::getAM5Offset(MO2.getImm());
   unsigned Op = ARM_AM::getAM5Op(MO2.getImm());
-  if (ImmOffs || Op == ARM_AM::sub) {
+  if (AlwaysPrintImm0 || ImmOffs || Op == ARM_AM::sub) {
     O << ", "
       << markup("<imm:")
       << "#"
@@ -1022,6 +1025,7 @@ void ARMInstPrinter::printT2SOOperand(const MCInst *MI, unsigned OpNum,
                    ARM_AM::getSORegOffset(MO2.getImm()), UseMarkup);
 }
 
+template <bool AlwaysPrintImm0>
 void ARMInstPrinter::printAddrModeImm12Operand(const MCInst *MI, unsigned OpNum,
                                                raw_ostream &O) {
   const MCOperand &MO1 = MI->getOperand(OpNum);
@@ -1042,13 +1046,13 @@ void ARMInstPrinter::printAddrModeImm12Operand(const MCInst *MI, unsigned OpNum,
     OffImm = 0;
   if (isSub) {
     O << ", "
-      << markup("<imm:") 
+      << markup("<imm:")
       << "#-" << -OffImm
       << markup(">");
   }
-  else if (OffImm > 0) {
+  else if (AlwaysPrintImm0 || OffImm > 0) {
     O << ", "
-      << markup("<imm:") 
+      << markup("<imm:")
       << "#" << OffImm
       << markup(">");
   }
diff --git a/lib/Target/ARM/InstPrinter/ARMInstPrinter.h b/lib/Target/ARM/InstPrinter/ARMInstPrinter.h
index edff75d886..344104e873 100644
--- a/lib/Target/ARM/InstPrinter/ARMInstPrinter.h
+++ b/lib/Target/ARM/InstPrinter/ARMInstPrinter.h
@@ -47,12 +47,13 @@ public:
                                   raw_ostream &O);
   void printAddrMode2OffsetOperand(const MCInst *MI, unsigned OpNum,
                                    raw_ostream &O);
-
+  template <bool AlwaysPrintImm0>
   void printAddrMode3Operand(const MCInst *MI, unsigned OpNum, raw_ostream &O);
   void printAddrMode3OffsetOperand(const MCInst *MI, unsigned OpNum,
                                    raw_ostream &O);
   void printAM3PostIndexOp(const MCInst *MI, unsigned Op, raw_ostream &O);
-  void printAM3PreOrOffsetIndexOp(const MCInst *MI, unsigned Op,raw_ostream &O);
+  void printAM3PreOrOffsetIndexOp(const MCInst *MI, unsigned Op, raw_ostream &O,
+                                  bool AlwaysPrintImm0);
   void printPostIdxImm8Operand(const MCInst *MI, unsigned OpNum,
                                raw_ostream &O);
   void printPostIdxRegOperand(const MCInst *MI, unsigned OpNum, raw_ostream &O);
@@ -60,6 +61,7 @@ public:
                                raw_ostream &O);
 
   void printLdStmModeOperand(const MCInst *MI, unsigned OpNum, raw_ostream &O);
+  template <bool AlwaysPrintImm0>
   void printAddrMode5Operand(const MCInst *MI, unsigned OpNum, raw_ostream &O);
   void printAddrMode6Operand(const MCInst *MI, unsigned OpNum, raw_ostream &O);
   void printAddrMode7Operand(const MCInst *MI, unsigned OpNum, raw_ostream &O);
@@ -91,6 +93,7 @@ public:
                                    raw_ostream &O);
 
   void printT2SOOperand(const MCInst *MI, unsigned OpNum, raw_ostream &O);
+  template<bool AlwaysPrintImm0>
   void printAddrModeImm12Operand(const MCInst *MI, unsigned OpNum,
                                  raw_ostream &O);
   void printT2AddrModeImm8Operand(const MCInst *MI, unsigned OpNum,
diff --git a/test/MC/ARM/basic-arm-instructions.s b/test/MC/ARM/basic-arm-instructions.s
index f73ae1449d..a5f4501680 100644
--- a/test/MC/ARM/basic-arm-instructions.s
+++ b/test/MC/ARM/basic-arm-instructions.s
@@ -2309,7 +2309,7 @@ Lforward:
         strpl	r3, [r10, #0]!
 
 @ CHECK: strpl	r3, [r10, #-0]!         @ encoding: [0x00,0x30,0x2a,0x55]
-@ CHECK: strpl	r3, [r10]!              @ encoding: [0x00,0x30,0xaa,0x55]
+@ CHECK: strpl	r3, [r10, #0]!          @ encoding: [0x00,0x30,0xaa,0x55]
 
 @------------------------------------------------------------------------------
 @ SUB
diff --git a/test/MC/Disassembler/ARM/arm-tests.txt b/test/MC/Disassembler/ARM/arm-tests.txt
index 0c9aaab38c..98daaa7649 100644
--- a/test/MC/Disassembler/ARM/arm-tests.txt
+++ b/test/MC/Disassembler/ARM/arm-tests.txt
@@ -51,24 +51,48 @@
 # CHECKx:	ldclvc	p5, cr15, [r8], #-0
 #0x00 0xf5 0x78 0x7c
 
+# CHECK:        ldc     p13, c9, [r2, #0]!
+0x00 0x9d 0xb2 0xed
+
+# CHECK:        ldcl    p1, c9, [r3, #0]!
+0x00 0x91 0xf3 0xed
+
 # CHECK:	ldr	r0, [r2], #15
 0x0f 0x00 0x92 0xe4
 
 # CHECK:	ldr	r5, [r7, -r10, lsl #2]
 0x0a 0x51 0x17 0xe7
 
+# CHECK:        ldr     r4, [r5, #0]!
+0x00 0x40 0xb5 0xe5
+
+# CHECK:        ldrb    lr, [r10, #0]!
+0x00 0xe0 0xfa 0xe5
+
+# CHECK:	ldrd	r4, r5, [r0, #0]!
+0xd0 0x40 0xe0 0xe1
+
 # CHECK:	ldrh	r0, [r2], #0
 0xb0 0x00 0xd2 0xe0
 
 # CHECK:	ldrh	r0, [r2]
 0xb0 0x00 0xd2 0xe1
 
+# CHECK:	ldrh    lr, [sp, #0]!
+0xb0 0xe0 0xfd 0xe1
+
 # CHECK:	ldrht	r0, [r2], #15
 0xbf 0x00 0xf2 0xe0
 
+# CHECK:        ldrsb   r1, [lr, #0]!
+0xd0 0x10 0xfe 0xe1
+
 # CHECK:	ldrsbtvs	lr, [r2], -r9
 0xd9 0xe0 0x32 0x60
 
+# CHECK:        ldrsh   r9, [r1, #0]
+0xf0 0x90 0xf1 0xe1
+
 # CHECK:	lsls	r0, r2, #31
 0x82 0x0f 0xb0 0xe1
 
@@ -245,9 +269,27 @@
 # CHECK:	stc	p2, c4, [r9], {157}
 0x9d 0x42 0x89 0xec
 
+# CHECK:        stc     p15, c0, [r3, #0]!
+0x00 0x0f 0xa3 0xed
+
 # CHECK:	stc2	p2, c4, [r9], {157}
 0x9d 0x42 0x89 0xfc
 
+# CHECK:	stcl    p13, c12, [r9, #0]!
+0x00 0xcd 0xe9 0xed
+
+# CHECK:        str     pc, [r11, #0]!
+0x00 0xf0 0xab 0xe5
+
+# CHECK:        strb    r9, [r10, #0]!
+0x00 0x90 0xea 0xe5
+
+# CHECK:        strd    r12, sp, [r6, #0]!
+0xf0 0xc0 0xe6 0xe1
+
+# CHECK:        strh    r7, [r9, #0]!
+0xb0 0x70 0xe9 0xe1
+
 # CHECK:	bne #-24
 0xfa 0xff 0xff 0x1a