[DebugInfo][ARM] Fix noreg case when checking if it is an addImm

[djtodoro]

Summary

This is just part of the D73534, but this does not need to wait for the re-landing of the whole patch, since it fixes a build failure within an ARM buildbot.

(No need to review this one, it has already been reviewed at the D73534)

[djtodoro]

The commit: 58d9e8194e4e4ed18175400792030920a3bb7636.

llvm/lib/Target/AArch64/AArch64InstrInfo.cpp

 
 Optional<RegImmPair> AArch64InstrInfo::isAddImmediate(const MachineInstr &MI,
                                                       Register Reg) const {
   int Sign = 1;
   int64_t Offset = 0;
 
   // TODO: Handle cases where Reg is a super- or sub-register of the
   // destination register.
-  if (Reg != MI.getOperand(0).getReg())
+  const MachineOperand &Op0 = MI.getOperand(0);
+  if (!Op0.isReg() || Reg != Op0.getReg())
     return None;
 
   switch (MI.getOpcode()) {
   default:
     return None;
   case AArch64::SUBWri:
   case AArch64::SUBXri:
   case AArch64::SUBSWri:

llvm/lib/Target/ARM/ARMBaseInstrInfo.cpp

 Optional<RegImmPair> ARMBaseInstrInfo::isAddImmediate(const MachineInstr &MI,
                                                       Register Reg) const {
   int Sign = 1;
   unsigned Opcode = MI.getOpcode();
   int64_t Offset = 0;
 
   // TODO: Handle cases where Reg is a super- or sub-register of the
   // destination register.
-  if (Reg != MI.getOperand(0).getReg())
+  const MachineOperand &Op0 = MI.getOperand(0);
+  if (!Op0.isReg() || Reg != Op0.getReg())
     return None;
 
   // We describe SUBri or ADDri instructions.
   if (Opcode == ARM::SUBri)
     Sign = -1;
   else if (Opcode != ARM::ADDri)
     return None;
 
   // TODO: Third operand can be global address (usually some string). Since
   //       strings can be relocated we cannot calculate their offsets for
   //       now.
-  if (!MI.getOperand(0).isReg() || !MI.getOperand(1).isReg() ||
-      !MI.getOperand(2).isImm())
+  if (!MI.getOperand(1).isReg() || !MI.getOperand(2).isImm())
     return None;
 
   Offset = MI.getOperand(2).getImm() * Sign;
   return RegImmPair{MI.getOperand(1).getReg(), Offset};
 }
 
 bool llvm::registerDefinedBetween(unsigned Reg,
                                   MachineBasicBlock::iterator From,

llvm/test/DebugInfo/MIR/ARM/dbgcallsite-noreg-is-imm-check.mir

+# RUN: llc -debug-entry-values -mtriple=armebv6k-unknown-linux-gnueabihf -filetype=obj -start-after=machineverifier %s -o -| llvm-dwarfdump - | FileCheck %s --implicit-check-not=DW_TAG_GNU_call_site_parameter
+
+## The test was handmade.
+
+--- |
+  ; ModuleID = 'test.c'
+  source_filename = "test.c"
+  target datalayout = "E-m:e-p:32:32-Fi8-i64:64-v128:64:128-a:0:32-n32-S64"
+  target triple = "armebv6k-unknown-linux-gnueabihf"
+
+  ; Function Attrs: nounwind
+  define dso_local arm_aapcscc i32 @func1(i32 %arg1) local_unnamed_addr !dbg !14 {
+  entry:
+    %add = add nsw i32 %arg1, 2, !dbg !19
+    %a = alloca i32, align 4
+    call void @llvm.dbg.value(metadata i32 %arg1, metadata !18, metadata !DIExpression()), !dbg !19
+    %call = call arm_aapcscc i32 @func2(i32 %add), !dbg !19
+    ret i32  0, !dbg !19
+  }
+
+  declare !dbg !4 dso_local arm_aapcscc i32 @func2(i32) local_unnamed_addr
+
+  ; Function Attrs: nounwind readnone speculatable willreturn
+  declare void @llvm.dbg.value(metadata, metadata, metadata)
+
+  !llvm.dbg.cu = !{!0}
+  !llvm.module.flags = !{!9, !10, !11, !12}
+  !llvm.ident = !{!13}
+
+  !0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 10.0.0", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, retainedTypes: !3, nameTableKind: None)
+  !1 = !DIFile(filename: "test.c", directory: "/")
+  !2 = !{}
+  !3 = !{!4}
+  !4 = !DISubprogram(name: "func2", scope: !1, file: !1, line: 8, type: !5, flags: DIFlagPrototyped, spFlags: DISPFlagOptimized, retainedNodes: !2)
+  !5 = !DISubroutineType(types: !6)
+  !6 = !{!7, !7, !7, !8}
+  !7 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+  !8 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !7, size: 32)
+  !9 = !{i32 2, !"Dwarf Version", i32 4}
+  !10 = !{i32 2, !"Debug Info Version", i32 3}
+  !11 = !{i32 1, !"wchar_size", i32 4}
+  !12 = !{i32 1, !"min_enum_size", i32 4}
+  !13 = !{!"clang version 10.0.0"}
+  !14 = distinct !DISubprogram(name: "func1", scope: !1, file: !1, line: 9, type: !15, scopeLine: 9, flags: DIFlagPrototyped | DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !17)
+  !15 = !DISubroutineType(types: !16)
+  !16 = !{!7, !7, !7, !7}
+  !17 = !{!18}
+  !18 = !DILocalVariable(name: "arg1", arg: 1, scope: !14, file: !1, line: 9, type: !7)
+  !19 = !DILocation(line: 0, scope: !14)
+...
+---
+name:            func1
+alignment:       4
+callSites:
+  - { bb: 0, offset: 11, fwdArgRegs:
+      - { arg: 0, reg: '$r0' } }
+body:             |
+  bb.0.entry:
+    liveins: $r0, $r1, $r2, $r4, $r10, $lr
+
+    DBG_VALUE $r0, $noreg, !18, !DIExpression(), debug-location !19
+    $sp = frame-setup STMDB_UPD $sp, 14, $noreg, killed $r4, killed $r10, $r11, killed $lr
+    frame-setup CFI_INSTRUCTION def_cfa_offset 16
+    frame-setup CFI_INSTRUCTION offset $lr, -4
+    frame-setup CFI_INSTRUCTION offset $r11, -8
+    frame-setup CFI_INSTRUCTION offset $r10, -12
+    frame-setup CFI_INSTRUCTION offset $r4, -16
+    $r11 = frame-setup ADDri $sp, 8, 14, $noreg, $noreg
+    frame-setup CFI_INSTRUCTION def_cfa $r11, 8
+    $sp = frame-setup SUBri $sp, 8, 14, $noreg, $noreg
+    INLINEASM &"rev $0, $1", 0, 327690, def renamable $r0, 327689, killed renamable $r4, 0, debug-location !19
+    BL @func2, csr_aapcs, implicit-def dead $lr, implicit $sp, implicit killed $r0, implicit killed $r1, implicit killed $r2, implicit-def $sp, implicit-def $r0, debug-location !19
+    BX_RET 14, $noreg, implicit killed $r0, debug-location !19
+
+...