[DPWBS-1149] fix(FrameLowering): skip debug instructions in processFu…

…nctionBeforeFrameFinalized

This fixes a crash when building with debug info enabled when a debug instruction
uses the stack.

llvm/lib/Target/TriCore/TriCoreFrameLowering.cpp

@@ -367,6 +367,10 @@ void TriCoreFrameLowering::processFunctionBeforeFrameFinalized(
   unsigned OffsetBits = -1;
   for (const MachineBasicBlock &MBB : MF) {
     for (const MachineInstr &MI : MBB) {
+      // Skip debug instructions
+      if (MI.isDebugInstr())
+        continue;
+
       // Only look at instructions which have a frame index operand
       for (const MachineOperand &MO : MI.operands()) {
         if (MO.isFI()) {

llvm/lib/Target/TriCore/TriCoreRegisterInfo.cpp

@@ -93,6 +93,9 @@ void TriCoreRegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II,
   const TriCoreInstrInfo *TII =
       MF.getSubtarget<TriCoreSubtarget>().getInstrInfo();
 
+  assert(!MI.isDebugValue() &&
+         "DBG_VALUE should have been handled by target-independent code");
+
   // Calculate the offset of the frame index and the frame register
   const int FrameIndex = MI.getOperand(FIOperandNum).getIndex();
   unsigned FrameReg;

llvm/test/CodeGen/TriCore/elim-frame-index-dbg-value.mir

@@ -0,0 +1,64 @@
+# NOTE: Assertions have been autogenerated by utils/update_mir_test_checks.py
+# RUN: llc -mtriple=tricore -run-pass=prologepilog -verify-machineinstrs %s -o - | FileCheck %s
+
+# Check that a DBG_VALUE instruction with a frame index operand does not cause
+# a crash before and during frame-index elimination.
+
+--- |
+  ; Function Attrs: noinline nounwind optnone
+  define dso_local void @test_dbg_value_ignored({ double, double }* noalias sret %agg.result, { double, double }* %x) #0 !dbg !7 {
+  entry:
+    unreachable
+  }
+
+  attributes #0 = { noinline nounwind optnone "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "frame-pointer"="all" "less-precise-fpmad"="false" "min-legal-vector-width"="0" "no-builtins" "no-infs-fp-math"="false" "no-jump-tables"="false" "no-nans-fp-math"="false" "no-signed-zeros-fp-math"="false" "no-trapping-math"="false" "stack-protector-buffer-size"="8" "target-cpu"="tc2xx" "target-features"="+tc161" "unsafe-fp-math"="false" "use-soft-float"="false" }
+  attributes #1 = { nounwind readnone speculatable willreturn }
+  attributes #2 = { "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "frame-pointer"="all" "less-precise-fpmad"="false" "no-builtins" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "no-signed-zeros-fp-math"="false" "no-trapping-math"="false" "stack-protector-buffer-size"="8" "target-cpu"="tc2xx" "target-features"="+tc161" "unsafe-fp-math"="false" "use-soft-float"="false" }
+  attributes #3 = { nounwind }
+  attributes #4 = { nobuiltin "no-builtins" }
+
+  !llvm.dbg.cu = !{!0}
+  !llvm.module.flags = !{!3, !4, !5}
+  !llvm.ident = !{!6}
+
+  !0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 11.0.0 (ssh://git@bitbucket-server.software.htc:7999/toolchain/llvm-project.git 1d1bcd3eb2181697497b5c82dc130b85ca9ca9c0)", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, splitDebugInlining: false, nameTableKind: None)
+  !1 = !DIFile(filename: "/home/jenkins/workspace/toolchain/dinkum-libc/dinkum/source/csinhl.c", directory: "/home/dominik/workspace/playground")
+  !2 = !{}
+  !3 = !{i32 7, !"Dwarf Version", i32 4}
+  !4 = !{i32 2, !"Debug Info Version", i32 3}
+  !5 = !{i32 1, !"wchar_size", i32 4}
+  !6 = !{!"clang version 11.0.0 (ssh://git@bitbucket-server.software.htc:7999/toolchain/llvm-project.git 1d1bcd3eb2181697497b5c82dc130b85ca9ca9c0)"}
+  !7 = distinct !DISubprogram(name: "csinhl", scope: !8, file: !8, line: 6, type: !9, scopeLine: 7, flags: DIFlagPrototyped, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !2)
+  !8 = !DIFile(filename: "jenkins/workspace/toolchain/dinkum-libc/dinkum/source/xxcsinh.h", directory: "/home")
+  !9 = !DISubroutineType(types: !10)
+  !10 = !{!11, !11}
+  !11 = !DIDerivedType(tag: DW_TAG_typedef, name: "_Lcomplex", file: !12, line: 89, baseType: !13)
+  !12 = !DIFile(filename: "jenkins/workspace/toolchain/dinkum-libc/dinkum/include/c/complex.h", directory: "/home")
+  !13 = !DIBasicType(name: "complex", size: 128, encoding: DW_ATE_complex_float)
+  !14 = !DILocalVariable(name: "x", arg: 1, scope: !7, file: !8, line: 6, type: !11)
+  !15 = !DILocation(line: 6, column: 30, scope: !7)
+
+...
+---
+name:            test_dbg_value_ignored
+alignment:       1
+legalized:       true
+regBankSelected: true
+selected:        true
+tracksRegLiveness: true
+stack:
+  - { id: 0, name: '', type: spill-slot, offset: 0, size: 4, alignment: 4,
+      stack-id: default, callee-saved-register: '', callee-saved-restored: true,
+      debug-info-variable: '', debug-info-expression: '', debug-info-location: '' }
+callSites:       []
+constants:       []
+machineFunctionInfo: {}
+body:             |
+  bb.1.entry:
+    ; CHECK-LABEL: name: test_dbg_value_ignored
+    ; CHECK: $a14 = frame-setup MOVAA_aa $a10
+    ; CHECK: $a10 = frame-setup LEA_aac $a10, -8
+    ; CHECK: frame-setup CFI_INSTRUCTION def_cfa $a14, 0
+    ; CHECK: DBG_VALUE $a14, 0
+    DBG_VALUE %stack.0, 0, !14, !DIExpression(DW_OP_deref), debug-location !15
+...