[AVR] Fix parsing & emitting relative jumps

llvm/lib/Target/AVR/AsmParser/AVRAsmParser.cpp

@@ -72,7 +72,7 @@ class AVRAsmParser : public MCTargetAsmParser {
   int parseRegisterName();
   int parseRegister(bool RestoreOnFailure = false);
   bool tryParseRegisterOperand(OperandVector &Operands);
-  bool tryParseExpression(OperandVector &Operands);
+  bool tryParseExpression(OperandVector &Operands, int64_t offset);
   bool tryParseRelocExpression(OperandVector &Operands);
   void eatComma();
 
@@ -418,7 +418,7 @@ bool AVRAsmParser::tryParseRegisterOperand(OperandVector &Operands) {
   return false;
 }
 
-bool AVRAsmParser::tryParseExpression(OperandVector &Operands) {
+bool AVRAsmParser::tryParseExpression(OperandVector &Operands, int64_t offset) {
   SMLoc S = Parser.getTok().getLoc();
 
   if (!tryParseRelocExpression(Operands))
@@ -437,6 +437,11 @@ bool AVRAsmParser::tryParseExpression(OperandVector &Operands) {
   if (getParser().parseExpression(Expression))
     return true;
 
+  if (offset) {
+    Expression = MCBinaryExpr::createAdd(
+        Expression, MCConstantExpr::create(offset, getContext()), getContext());
+  }
+
   SMLoc E = SMLoc::getFromPointer(Parser.getTok().getLoc().getPointer() - 1);
   Operands.push_back(AVROperand::CreateImm(Expression, S, E));
   return false;
@@ -529,8 +534,9 @@ bool AVRAsmParser::parseOperand(OperandVector &Operands, bool maybeReg) {
     [[fallthrough]];
   case AsmToken::LParen:
   case AsmToken::Integer:
+    return tryParseExpression(Operands, 0);
   case AsmToken::Dot:
-    return tryParseExpression(Operands);
+    return tryParseExpression(Operands, 2);
   case AsmToken::Plus:
   case AsmToken::Minus: {
     // If the sign preceeds a number, parse the number,
@@ -540,7 +546,7 @@ bool AVRAsmParser::parseOperand(OperandVector &Operands, bool maybeReg) {
     case AsmToken::BigNum:
     case AsmToken::Identifier:
     case AsmToken::Real:
-      if (!tryParseExpression(Operands))
+      if (!tryParseExpression(Operands, 0))
         return false;
       break;
     default:
@@ -643,6 +649,7 @@ bool AVRAsmParser::ParseInstruction(ParseInstructionInfo &Info,
     // These specific operands should be treated as addresses/symbols/labels,
     // other than registers.
     bool maybeReg = true;
+
     if (OperandNum == 1) {
       std::array<StringRef, 8> Insts = {"lds", "adiw", "sbiw", "ldi"};
       for (auto Inst : Insts) {

llvm/lib/Target/AVR/MCTargetDesc/AVRAsmBackend.cpp

@@ -94,6 +94,9 @@ static void adjustRelativeBranch(unsigned Size, const MCFixup &Fixup,
 
   // Rightshifts the value by one.
   AVR::fixups::adjustBranchTarget(Value);
+
+  // Jumps are relative to the current instruction.
+  Value -= 1;
 }
 
 /// 22-bit absolute fixup.
@@ -513,15 +516,10 @@ bool AVRAsmBackend::shouldForceRelocation(const MCAssembler &Asm,
   switch ((unsigned)Fixup.getKind()) {
   default:
     return Fixup.getKind() >= FirstLiteralRelocationKind;
-  // Fixups which should always be recorded as relocations.
   case AVR::fixup_7_pcrel:
   case AVR::fixup_13_pcrel:
-    // Do not force relocation for PC relative branch like 'rjmp .',
-    // 'rcall . - off' and 'breq . + off'.
-    if (const auto *SymA = Target.getSymA())
-      if (SymA->getSymbol().getName().size() == 0)
-        return false;
-    [[fallthrough]];
+    // Always resolve relocations for PC-relative branches
+    return false;
   case AVR::fixup_call:
     return true;
   }

llvm/test/CodeGen/AVR/jmp.ll

@@ -0,0 +1,25 @@
+; RUN: llc -filetype=obj -mtriple=avr < %s | llvm-objdump -dr --no-show-raw-insn - | FileCheck %s
+
+define i8 @foo(i8 %a) {
+bb0:
+  %0 = tail call i8 @bar(i8 %a)
+  %1 = icmp eq i8 %0, 123
+  br i1 %1, label %bb1, label %bb2
+
+bb1:
+  ret i8 100
+
+bb2:
+  ret i8 200
+}
+
+declare i8 @bar(i8);
+
+; CHECK: rcall   .-2
+; CHECK-NEXT: 00000000: R_AVR_13_PCREL bar
+; CHECK-NEXT: cpi     r24, 0x7b
+; CHECK-NEXT: brne    .+4
+; CHECK-NEXT: ldi     r24, 0x64
+; CHECK-NEXT: ret
+; CHECK-NEXT: ldi     r24, 0xc8
+; CHECK-NEXT: ret

llvm/test/MC/AVR/inst-brbc.s

@@ -3,22 +3,23 @@
 ; RUN:     | llvm-objdump -d - | FileCheck --check-prefix=INST %s
 
 foo:
-
   brbc 3, .+8
   brbc 0, .-16
   .short 0xf759
   .short 0xf752
   .short 0xf74c
   .short 0xf4c7
 
-; CHECK: brvc .Ltmp0+8              ; encoding: [0bAAAAA011,0b111101AA]
-; CHECK:                            ; fixup A - offset: 0, value: .Ltmp0+8, kind: fixup_7_pcrel
-; CHECK: brcc .Ltmp1-16             ; encoding: [0bAAAAA000,0b111101AA]
-; CHECK:                            ; fixup A - offset: 0, value: .Ltmp1-16, kind: fixup_7_pcrel
+; CHECK: brvc (.Ltmp0+8)+2   ; encoding: [0bAAAAA011,0b111101AA]
+; CHECK-NEXT:                ; fixup A - offset: 0, value: (.Ltmp0+8)+2, kind: fixup_7_pcrel
+;
+; CHECK: brcc (.Ltmp1-16)+2  ; encoding: [0bAAAAA000,0b111101AA]
+; CHECK-NEXT:                ; fixup A - offset: 0, value: (.Ltmp1-16)+2, kind: fixup_7_pcrel
 
-; INST: 23 f4   brvc .+8
-; INST: c0 f7   brsh .-16
-; INST: 59 f7   brne .-42
-; INST: 52 f7   brpl .-44
-; INST: 4c f7   brge .-46
-; INST: c7 f4   brid .+48
+; INST-LABEL: <foo>:
+; INST-NEXT: 23 f4   brvc .+8
+; INST-NEXT: c0 f7   brsh .-16
+; INST-NEXT: 59 f7   brne .-42
+; INST-NEXT: 52 f7   brpl .-44
+; INST-NEXT: 4c f7   brge .-46
+; INST-NEXT: c7 f4   brid .+48

llvm/test/MC/AVR/inst-brbs.s

@@ -3,22 +3,22 @@
 ; RUN:     | llvm-objdump -d - | FileCheck --check-prefix=INST %s
 
 foo:
-
   brbs 3, .+8
   brbs 0, .-12
   .short 0xf359
   .short 0xf352
   .short 0xf34c
   .short 0xf077
 
-; CHECK: brvs .Ltmp0+8              ; encoding: [0bAAAAA011,0b111100AA]
-; CHECK:                            ; fixup A - offset: 0, value: .Ltmp0+8, kind: fixup_7_pcrel
-; CHECK: brcs .Ltmp1-12             ; encoding: [0bAAAAA000,0b111100AA]
-; CHECK:                            ; fixup A - offset: 0, value: .Ltmp1-12, kind: fixup_7_pcrel
+; CHECK: brvs (.Ltmp0+8)+2   ; encoding: [0bAAAAA011,0b111100AA]
+; CHECK-NEXT:                ; fixup A - offset: 0, value: (.Ltmp0+8)+2, kind: fixup_7_pcrel
+; CHECK: brcs (.Ltmp1-12)+2  ; encoding: [0bAAAAA000,0b111100AA]
+; CHECK-NEXT:                ; fixup A - offset: 0, value: (.Ltmp1-12)+2, kind: fixup_7_pcrel
 
-; INST: 23 f0   brvs .+8
-; INST: d0 f3   brlo .-12
-; INST: 59 f3   breq .-42
-; INST: 52 f3   brmi .-44
-; INST: 4c f3   brlt .-46
-; INST: 77 f0   brie .+28
+; INST-LABEL: <foo>:
+; INST-NEXT: 23 f0   brvs .+8
+; INST-NEXT: d0 f3   brlo .-12
+; INST-NEXT: 59 f3   breq .-42
+; INST-NEXT: 52 f3   brmi .-44
+; INST-NEXT: 4c f3   brlt .-46
+; INST-NEXT: 77 f0   brie .+28

llvm/test/MC/AVR/inst-brcc.s

@@ -0,0 +1,28 @@
+; RUN: llvm-mc -triple avr -show-encoding < %s | FileCheck %s
+;
+; RUN: llvm-mc -filetype=obj -triple avr < %s \
+; RUN:     | llvm-objdump -d - \
+; RUN:     | FileCheck --check-prefix=INST %s
+
+foo:
+  brcc .+66
+  brcc .-22
+  brbc 0, .+66
+  brbc 0, bar
+
+bar:
+
+; CHECK: brcc (.Ltmp0+66)+2  ; encoding: [0bAAAAA000,0b111101AA]
+; CHECK-NEXT:                ;   fixup A - offset: 0, value: (.Ltmp0+66)+2, kind: fixup_7_pcrel
+; CHECK: brcc (.Ltmp1-22)+2  ; encoding: [0bAAAAA000,0b111101AA]
+; CHECK-NEXT:                ;   fixup A - offset: 0, value: (.Ltmp1-22)+2, kind: fixup_7_pcrel
+; CHECK: brcc (.Ltmp2+66)+2  ; encoding: [0bAAAAA000,0b111101AA]
+; CHECK-NEXT:                ;   fixup A - offset: 0, value: (.Ltmp2+66)+2, kind: fixup_7_pcrel
+; CHECK: brcc bar            ; encoding: [0bAAAAA000,0b111101AA]
+; CHECK-NEXT:                ;   fixup A - offset: 0, value: bar, kind: fixup_7_pcrel
+
+; INST-LABEL: <foo>:
+; INST-NEXT: 08 f5      brsh .+66
+; INST-NEXT: a8 f7      brsh .-22
+; INST-NEXT: 08 f5      brsh .+66
+; INST-NEXT: 00 f4      brsh .+0

llvm/test/MC/AVR/inst-brcs.s

@@ -0,0 +1,28 @@
+; RUN: llvm-mc -triple avr -show-encoding < %s | FileCheck %s
+;
+; RUN: llvm-mc -filetype=obj -triple avr < %s \
+; RUN:     | llvm-objdump -d - \
+; RUN:     | FileCheck --check-prefix=INST %s
+
+foo:
+  brcs .+8
+  brcs .+4
+  brbs 0, .+8
+  brbs 0, bar
+
+bar:
+
+; CHECK: brcs (.Ltmp0+8)+2  ; encoding: [0bAAAAA000,0b111100AA]
+; CHECK-NEXT:               ;   fixup A - offset: 0, value: (.Ltmp0+8)+2, kind: fixup_7_pcrel
+; CHECK: brcs (.Ltmp1+4)+2  ; encoding: [0bAAAAA000,0b111100AA]
+; CHECK-NEXT:               ;   fixup A - offset: 0, value: (.Ltmp1+4)+2, kind: fixup_7_pcrel
+; CHECK: brcs (.Ltmp2+8)+2  ; encoding: [0bAAAAA000,0b111100AA]
+; CHECK-NEXT:               ;   fixup A - offset: 0, value: (.Ltmp2+8)+2, kind: fixup_7_pcrel
+; CHECK: brcs bar           ; encoding: [0bAAAAA000,0b111100AA]
+; CHECK-NEXT:               ;   fixup A - offset: 0, value: bar, kind: fixup_7_pcrel
+
+; INST-LABEL: <foo>:
+; INST-NEXT: 20 f0      brlo .+8
+; INST-NEXT: 10 f0      brlo .+4
+; INST-NEXT: 20 f0      brlo .+8
+; INST-NEXT: 00 f0      brlo .+0

llvm/test/MC/AVR/inst-breq.s

@@ -0,0 +1,28 @@
+; RUN: llvm-mc -triple avr -show-encoding < %s | FileCheck %s
+;
+; RUN: llvm-mc -filetype=obj -triple avr < %s \
+; RUN:     | llvm-objdump -d - \
+; RUN:     | FileCheck --check-prefix=INST %s
+
+foo:
+  breq .-18
+  breq .-12
+  brbs 1, .-18
+  brbs 1, bar
+
+bar:
+
+; CHECK: breq    (.Ltmp0-18)+2     ; encoding: [0bAAAAA001,0b111100AA]
+; CHECK-NEXT:                      ;   fixup A - offset: 0, value: (.Ltmp0-18)+2, kind: fixup_7_pcrel
+; CHECK: breq    (.Ltmp1-12)+2     ; encoding: [0bAAAAA001,0b111100AA]
+; CHECK-NEXT:                      ;   fixup A - offset: 0, value: (.Ltmp1-12)+2, kind: fixup_7_pcrel
+; CHECK: brbs    1, (.Ltmp2-18)+2  ; encoding: [0bAAAAA001,0b111100AA]
+; CHECK-NEXT:                      ;   fixup A - offset: 0, value: (.Ltmp2-18)+2, kind: fixup_7_pcrel
+; CHECK: brbs    1, bar            ; encoding: [0bAAAAA001,0b111100AA]
+; CHECK-NEXT:                      ;   fixup A - offset: 0, value: bar, kind: fixup_7_pcrel
+
+; INST-LABEL: <foo>:
+; INST-NEXT: b9 f3      breq .-18
+; INST-NEXT: d1 f3      breq .-12
+; INST-NEXT: b9 f3      breq .-18
+; INST-NEXT: 01 f0      breq .+0

llvm/test/MC/AVR/inst-brge.s

@@ -0,0 +1,24 @@
+; RUN: llvm-mc -triple avr -show-encoding < %s | FileCheck %s
+;
+; RUN: llvm-mc -filetype=obj -triple avr < %s \
+; RUN:     | llvm-objdump -d - \
+; RUN:     | FileCheck --check-prefix=INST %s
+
+foo:
+  brge .+50
+  brge .+42
+  brge bar
+
+bar:
+
+; CHECK: brge (.Ltmp0+50)+2  ; encoding: [0bAAAAA100,0b111101AA]
+; CHECK-NEXT:                ;   fixup A - offset: 0, value: (.Ltmp0+50)+2, kind: fixup_7_pcrel
+; CHECK: brge (.Ltmp1+42)+2  ; encoding: [0bAAAAA100,0b111101AA]
+; CHECK-NEXT:                ;   fixup A - offset: 0, value: (.Ltmp1+42)+2, kind: fixup_7_pcrel
+; CHECK: brge bar            ; encoding: [0bAAAAA100,0b111101AA]
+; CHECK-NEXT:                ;   fixup A - offset: 0, value: bar, kind: fixup_7_pcrel
+
+; INST-LABEL: <foo>:
+; INST-NEXT: cc f4      brge .+50
+; INST-NEXT: ac f4      brge .+42
+; INST-NEXT: 04 f4      brge .+0

llvm/test/MC/AVR/inst-brhc.s

@@ -0,0 +1,24 @@
+; RUN: llvm-mc -triple avr -show-encoding < %s | FileCheck %s
+;
+; RUN: llvm-mc -filetype=obj -triple avr < %s \
+; RUN:     | llvm-objdump -d - \
+; RUN:     | FileCheck --check-prefix=INST %s
+
+foo:
+  brhc .+12
+  brhc .+14
+  brhc bar
+
+bar:
+
+; CHECK: brhc (.Ltmp0+12)+2  ; encoding: [0bAAAAA101,0b111101AA]
+; CHECK-NEXT:                ;   fixup A - offset: 0, value: (.Ltmp0+12)+2, kind: fixup_7_pcrel
+; CHECK: brhc (.Ltmp1+14)+2  ; encoding: [0bAAAAA101,0b111101AA]
+; CHECK-NEXT:                ;   fixup A - offset: 0, value: (.Ltmp1+14)+2, kind: fixup_7_pcrel
+; CHECK: brhc bar            ; encoding: [0bAAAAA101,0b111101AA]
+; CHECK-NEXT:                ;   fixup A - offset: 0, value: bar, kind: fixup_7_pcrel
+
+; INST-LABEL: <foo>:
+; INST-NEXT: 35 f4      brhc .+12
+; INST-NEXT: 3d f4      brhc .+14
+; INST-NEXT: 05 f4      brhc .+0

llvm/test/MC/AVR/inst-brhs.s

@@ -0,0 +1,24 @@
+; RUN: llvm-mc -triple avr -show-encoding < %s | FileCheck %s
+;
+; RUN: llvm-mc -filetype=obj -triple avr < %s \
+; RUN:     | llvm-objdump -d - \
+; RUN:     | FileCheck --check-prefix=INST %s
+
+foo:
+  brhs .-66
+  brhs .+14
+  brhs bar
+
+bar:
+
+; CHECK: brhs (.Ltmp0-66)+2  ; encoding: [0bAAAAA101,0b111100AA]
+; CHECK-NEXT:                ;   fixup A - offset: 0, value: (.Ltmp0-66)+2, kind: fixup_7_pcrel
+; CHECK: brhs (.Ltmp1+14)+2  ; encoding: [0bAAAAA101,0b111100AA]
+; CHECK-NEXT:                ;   fixup A - offset: 0, value: (.Ltmp1+14)+2, kind: fixup_7_pcrel
+; CHECK: brhs bar            ; encoding: [0bAAAAA101,0b111100AA]
+; CHECK-NEXT:                ;   fixup A - offset: 0, value: bar, kind: fixup_7_pcrel
+
+; INST-LABEL: <foo>:
+; INST-NEXT: fd f2      brhs .-66
+; INST-NEXT: 3d f0      brhs .+14
+; INST-NEXT: 05 f0      brhs .+0

llvm/test/MC/AVR/inst-brid.s

@@ -0,0 +1,24 @@
+; RUN: llvm-mc -triple avr -show-encoding < %s | FileCheck %s
+;
+; RUN: llvm-mc -filetype=obj -triple avr < %s \
+; RUN:     | llvm-objdump -d - \
+; RUN:     | FileCheck --check-prefix=INST %s
+
+foo:
+  brid .+42
+  brid .+62
+  brid bar
+
+bar:
+
+; CHECK: brid (.Ltmp0+42)+2  ; encoding: [0bAAAAA111,0b111101AA]
+; CHECK-NEXT:                ;   fixup A - offset: 0, value: (.Ltmp0+42)+2, kind: fixup_7_pcrel
+; CHECK: brid (.Ltmp1+62)+2  ; encoding: [0bAAAAA111,0b111101AA]
+; CHECK-NEXT:                ;   fixup A - offset: 0, value: (.Ltmp1+62)+2, kind: fixup_7_pcrel
+; CHECK: brid bar            ; encoding: [0bAAAAA111,0b111101AA]
+; CHECK-NEXT:                ;   fixup A - offset: 0, value: bar, kind: fixup_7_pcrel
+
+; INST-LABEL: <foo>:
+; INST-NEXT: af f4      brid .+42
+; INST-NEXT: ff f4      brid .+62
+; INST-NEXT: 07 f4      brid .+0

llvm/test/MC/AVR/inst-brie.s

@@ -0,0 +1,24 @@
+; RUN: llvm-mc -triple avr -show-encoding < %s | FileCheck %s
+;
+; RUN: llvm-mc -filetype=obj -triple avr < %s \
+; RUN:     | llvm-objdump -d - \
+; RUN:     | FileCheck --check-prefix=INST %s
+
+foo:
+  brie .+20
+  brie .+40
+  brie bar
+
+bar:
+
+; CHECK: brie (.Ltmp0+20)+2  ; encoding: [0bAAAAA111,0b111100AA]
+; CHECK-NEXT:                ;   fixup A - offset: 0, value: (.Ltmp0+20)+2, kind: fixup_7_pcrel
+; CHECK: brie (.Ltmp1+40)+2  ; encoding: [0bAAAAA111,0b111100AA]
+; CHECK-NEXT:                ;   fixup A - offset: 0, value: (.Ltmp1+40)+2, kind: fixup_7_pcrel
+; CHECK: brie bar            ; encoding: [0bAAAAA111,0b111100AA]
+; CHECK-NEXT:                ;   fixup A - offset: 0, value: bar, kind: fixup_7_pcrel
+
+; INST-LABEL: <foo>:
+; INST-NEXT: 57 f0      brie .+20
+; INST-NEXT: a7 f0      brie .+40
+; INST-NEXT: 07 f0      brie .+0