[AVR] Disassemble multiplication instructions

These can often only use a limited range of registers, and apparently need special decoding support. Differential Revision: https://reviews.llvm.org/D81971
llvm · Jun 23, 2020 · ec9efb8 · ec9efb8
1 parent 01c2209
commit ec9efb8
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diff --git a/llvm/lib/Target/AVR/AVRInstrFormats.td b/llvm/lib/Target/AVR/AVRInstrFormats.td
@@ -272,6 +272,8 @@ class FMUL2RdRr<bit f, dag outs, dag ins, string asmstr, list<dag> pattern>
   let Inst{8} = f;
   let Inst{7-4} = rd{3-0};
   let Inst{3-0} = rr{3-0};
+
+  let DecoderMethod = "decodeFMUL2RdRr";
 }
 
 // Special encoding for the FMUL family of instructions.
@@ -295,6 +297,8 @@ class FFMULRdRr<bits<2> f, dag outs, dag ins, string asmstr, list<dag> pattern>
   let Inst{6-4} = rd;
   let Inst{3} = f{0};
   let Inst{2-0} = rr;
+
+  let DecoderMethod = "decodeFFMULRdRr";
 }
 
 

diff --git a/llvm/lib/Target/AVR/Disassembler/AVRDisassembler.cpp b/llvm/lib/Target/AVR/Disassembler/AVRDisassembler.cpp
@@ -110,6 +110,12 @@ static DecodeStatus decodeCallTarget(MCInst &Inst, unsigned Insn,
 static DecodeStatus decodeFRd(MCInst &Inst, unsigned Insn,
                               uint64_t Address, const void *Decoder);
 
+static DecodeStatus decodeFFMULRdRr(MCInst &Inst, unsigned Insn,
+                                    uint64_t Address, const void *Decoder);
+
+static DecodeStatus decodeFMUL2RdRr(MCInst &Inst, unsigned Insn,
+                                    uint64_t Address, const void *Decoder);
+
 #include "AVRGenDisassemblerTables.inc"
 
 static DecodeStatus decodeFIOARr(MCInst &Inst, unsigned Insn,
@@ -161,6 +167,28 @@ static DecodeStatus decodeFRd(MCInst &Inst, unsigned Insn,
   return MCDisassembler::Success;
 }
 
+static DecodeStatus decodeFFMULRdRr(MCInst &Inst, unsigned Insn,
+                                    uint64_t Address, const void *Decoder) {
+  unsigned d = fieldFromInstruction(Insn, 4, 3) + 16;
+  unsigned r = fieldFromInstruction(Insn, 0, 3) + 16;
+  if (DecodeGPR8RegisterClass(Inst, d, Address, Decoder) == MCDisassembler::Fail)
+    return MCDisassembler::Fail;
+  if (DecodeGPR8RegisterClass(Inst, r, Address, Decoder) == MCDisassembler::Fail)
+    return MCDisassembler::Fail;
+  return MCDisassembler::Success;
+}
+
+static DecodeStatus decodeFMUL2RdRr(MCInst &Inst, unsigned Insn,
+                                    uint64_t Address, const void *Decoder) {
+  unsigned rd = fieldFromInstruction(Insn, 4, 4) + 16;
+  unsigned rr = fieldFromInstruction(Insn, 0, 4) + 16;
+  if (DecodeGPR8RegisterClass(Inst, rd, Address, Decoder) == MCDisassembler::Fail)
+    return MCDisassembler::Fail;
+  if (DecodeGPR8RegisterClass(Inst, rr, Address, Decoder) == MCDisassembler::Fail)
+    return MCDisassembler::Fail;
+  return MCDisassembler::Success;
+}
+
 static DecodeStatus readInstruction16(ArrayRef<uint8_t> Bytes, uint64_t Address,
                                       uint64_t &Size, uint32_t &Insn) {
   if (Bytes.size() < 2) {

diff --git a/llvm/test/MC/AVR/inst-fmul.s b/llvm/test/MC/AVR/inst-fmul.s
@@ -1,4 +1,5 @@
 ; RUN: llvm-mc -triple avr -mattr=mul -show-encoding < %s | FileCheck %s
+; RUN: llvm-mc -filetype=obj -triple avr -mattr=mul < %s | llvm-objdump -d --mattr=mul - | FileCheck -check-prefix=CHECK-INST %s
 
 
 foo:
@@ -7,8 +8,19 @@ foo:
   fmul r19, r17
   fmul r21, r23
   fmul r23, r23
+  fmul r16, r16
+  fmul r16, r23
 
 ; CHECK: fmul r22, r16                   ; encoding: [0x68,0x03]
 ; CHECK: fmul r19, r17                   ; encoding: [0x39,0x03]
 ; CHECK: fmul r21, r23                   ; encoding: [0x5f,0x03]
 ; CHECK: fmul r23, r23                   ; encoding: [0x7f,0x03]
+; CHECK: fmul r16, r16                   ; encoding: [0x08,0x03]
+; CHECK: fmul r16, r23                   ; encoding: [0x0f,0x03]
+
+; CHECK-INST: fmul r22, r16
+; CHECK-INST: fmul r19, r17
+; CHECK-INST: fmul r21, r23
+; CHECK-INST: fmul r23, r23
+; CHECK-INST: fmul r16, r16
+; CHECK-INST: fmul r16, r23
diff --git a/llvm/test/MC/AVR/inst-fmuls.s b/llvm/test/MC/AVR/inst-fmuls.s
@@ -1,4 +1,5 @@
 ; RUN: llvm-mc -triple avr -mattr=mul -show-encoding < %s | FileCheck %s
+; RUN: llvm-mc -filetype=obj -triple avr -mattr=mul < %s | llvm-objdump -d --mattr=mul - | FileCheck -check-prefix=CHECK-INST %s
 
 
 foo:
@@ -12,3 +13,8 @@ foo:
 ; CHECK: fmuls r19, r17                   ; encoding: [0xb1,0x03]
 ; CHECK: fmuls r21, r23                   ; encoding: [0xd7,0x03]
 ; CHECK: fmuls r23, r23                   ; encoding: [0xf7,0x03]
+
+; CHECK-INST: fmuls r22, r16
+; CHECK-INST: fmuls r19, r17
+; CHECK-INST: fmuls r21, r23
+; CHECK-INST: fmuls r23, r23
diff --git a/llvm/test/MC/AVR/inst-fmulsu.s b/llvm/test/MC/AVR/inst-fmulsu.s
@@ -1,4 +1,5 @@
 ; RUN: llvm-mc -triple avr -mattr=mul -show-encoding < %s | FileCheck %s
+; RUN: llvm-mc -filetype=obj -triple avr -mattr=mul < %s | llvm-objdump -d --mattr=mul - | FileCheck -check-prefix=CHECK-INST %s
 
 
 foo:
@@ -12,3 +13,8 @@ foo:
 ; CHECK: fmulsu r19, r17                   ; encoding: [0xb9,0x03]
 ; CHECK: fmulsu r21, r23                   ; encoding: [0xdf,0x03]
 ; CHECK: fmulsu r23, r23                   ; encoding: [0xff,0x03]
+
+; CHECK-INST: fmulsu r22, r16
+; CHECK-INST: fmulsu r19, r17
+; CHECK-INST: fmulsu r21, r23
+; CHECK-INST: fmulsu r23, r23
diff --git a/llvm/test/MC/AVR/inst-muls.s b/llvm/test/MC/AVR/inst-muls.s
@@ -1,4 +1,5 @@
 ; RUN: llvm-mc -triple avr -mattr=mul -show-encoding < %s | FileCheck %s
+; RUN: llvm-mc -filetype=obj -triple avr -mattr=mul < %s | llvm-objdump -d --mattr=mul - | FileCheck -check-prefix=CHECK-INST %s
 
 
 foo:
@@ -7,8 +8,19 @@ foo:
   muls r19, r17
   muls r28, r31
   muls r31, r31
+  muls r16, r16
+  muls r16, r31
 
 ; CHECK: muls r22, r16                   ; encoding: [0x60,0x02]
 ; CHECK: muls r19, r17                   ; encoding: [0x31,0x02]
 ; CHECK: muls r28, r31                   ; encoding: [0xcf,0x02]
 ; CHECK: muls r31, r31                   ; encoding: [0xff,0x02]
+; CHECK: muls r16, r16                   ; encoding: [0x00,0x02]
+; CHECK: muls r16, r31                   ; encoding: [0x0f,0x02]
+
+; CHECK-INST: muls r22, r16
+; CHECK-INST: muls r19, r17
+; CHECK-INST: muls r28, r31
+; CHECK-INST: muls r31, r31
+; CHECK-INST: muls r16, r16
+; CHECK-INST: muls r16, r31
diff --git a/llvm/test/MC/AVR/inst-mulsu.s b/llvm/test/MC/AVR/inst-mulsu.s
@@ -1,4 +1,5 @@
 ; RUN: llvm-mc -triple avr -mattr=mul -show-encoding < %s | FileCheck %s
+; RUN: llvm-mc -filetype=obj -triple avr -mattr=mul < %s | llvm-objdump -d --mattr=mul - | FileCheck -check-prefix=CHECK-INST %s
 
 
 foo:
@@ -12,3 +13,8 @@ foo:
 ; CHECK: mulsu r19, r17                   ; encoding: [0x31,0x03]
 ; CHECK: mulsu r21, r23                   ; encoding: [0x57,0x03]
 ; CHECK: mulsu r23, r23                   ; encoding: [0x77,0x03]
+
+; CHECK-INST: mulsu r22, r16
+; CHECK-INST: mulsu r19, r17
+; CHECK-INST: mulsu r21, r23
+; CHECK-INST: mulsu r23, r23