[CSInfo][MIPS] Update CSInfo in delay slot filler

In MipsDelaySlotFiller, when replacing old call-branch with
the compact branch instruction, an assertion is caused by erasing
the old call with unhandled CSInfo.
The problem was reported in PR48695.
This patch fixes it, by moving call site info from the old call
instruction to its replace.
​
Patch by Nikola Tesic
​
Differential revision: https://reviews.llvm.org/D94685

diff --git a/llvm/lib/Target/Mips/MipsDelaySlotFiller.cpp b/llvm/lib/Target/Mips/MipsDelaySlotFiller.cpp
index 18904d0..797d812 100644 (file)
--- a/llvm/lib/Target/Mips/MipsDelaySlotFiller.cpp
+++ b/llvm/lib/Target/Mips/MipsDelaySlotFiller.cpp
@@ -565,7 +565,11 @@ Iter MipsDelaySlotFiller::replaceWithCompactBranch(MachineBasicBlock &MBB,
   unsigned NewOpcode = TII->getEquivalentCompactForm(Branch);
   Branch = TII->genInstrWithNewOpc(NewOpcode, Branch);
 
-  std::next(Branch)->eraseFromParent();
+  auto *ToErase = cast<MachineInstr>(&*std::next(Branch));
+  // Update call site info for the Branch.
+  if (ToErase->shouldUpdateCallSiteInfo())
+    ToErase->getMF()->moveCallSiteInfo(ToErase, cast<MachineInstr>(&*Branch));
+  ToErase->eraseFromParent();
   return Branch;
 }
 

diff --git a/llvm/test/DebugInfo/MIR/Mips/call-site-info-update-delay-slot-filler.mir b/llvm/test/DebugInfo/MIR/Mips/call-site-info-update-delay-slot-filler.mir
new file mode 100644 (file)
index 0000000..999e783
--- /dev/null
+++ b/llvm/test/DebugInfo/MIR/Mips/call-site-info-update-delay-slot-filler.mir
@@ -0,0 +1,83 @@
+## Test mips32r6:
+# RUN: llc -mtriple mips-linux-gnu -emit-call-site-info -run-pass=mips-delay-slot-filler %s -o -| FileCheck %s
+
+## Following code is used for producing this test case.
+##
+## (*pm_power_off)();
+## machine_power_off() { pm_power_off(); }
+##
+## Used command:
+## clang --target=mips-linux-gnu -march=mips32r6 -g -O2 -c m.c -mllvm -stop-before=mips-delay-slot-filler
+
+## Confirm that call site info exists after mips-delay-slot-filler, although, 
+## the pass replaced the call instruction.
+# CHECK: callSites:
+# CHECK-NEXT: - { bb: {{.*}}, offset: {{.*}}, fwdArgRegs:
+
+--- |
+  ; ModuleID = 'm.c'
+  source_filename = "m.c"
+  target datalayout = "E-m:m-p:32:32-i8:8:32-i16:16:32-i64:64-n32-S64"
+  target triple = "mips-unknown-linux-gnu"
+  
+  @pm_power_off = dso_local local_unnamed_addr global i32 (...)* null, align 4, !dbg !0
+  
+  ; Function Attrs: nounwind
+  define dso_local i32 @machine_power_off() local_unnamed_addr #0 !dbg !14 {
+  entry:
+    %0 = load i32 ()*, i32 ()** bitcast (i32 (...)** @pm_power_off to i32 ()**), align 4, !dbg !17
+    %call = tail call i32 %0(), !dbg !17
+    ret i32 undef, !dbg !17
+  }
+  
+  attributes #0 = { "target-cpu"="mips32r6" }
+  
+  !llvm.dbg.cu = !{!2}
+  !llvm.module.flags = !{!10, !11, !12}
+  !llvm.ident = !{!13}
+  
+  !0 = !DIGlobalVariableExpression(var: !1, expr: !DIExpression())
+  !1 = distinct !DIGlobalVariable(name: "pm_power_off", scope: !2, file: !3, line: 1, type: !6, isLocal: false, isDefinition: true)
+  !2 = distinct !DICompileUnit(language: DW_LANG_C99, file: !3, producer: "clang version 12.0.0", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !4, globals: !5, splitDebugInlining: false, nameTableKind: None)
+  !3 = !DIFile(filename: "m.c", directory: "/dir")
+  !4 = !{}
+  !5 = !{!0}
+  !6 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !7, size: 32)
+  !7 = !DISubroutineType(types: !8)
+  !8 = !{!9, null}
+  !9 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+  !10 = !{i32 7, !"Dwarf Version", i32 4}
+  !11 = !{i32 2, !"Debug Info Version", i32 3}
+  !12 = !{i32 1, !"wchar_size", i32 4}
+  !13 = !{!"clang version 12.0.0"}
+  !14 = distinct !DISubprogram(name: "machine_power_off", scope: !3, file: !3, line: 2, type: !15, scopeLine: 2, flags: DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !2, retainedNodes: !4)
+  !15 = !DISubroutineType(types: !16)
+  !16 = !{!9}
+  !17 = !DILocation(line: 2, column: 23, scope: !14)
+
+...
+---
+name:            machine_power_off
+alignment:       4
+stack:
+  - { id: 0, name: '', type: spill-slot, offset: -4, size: 4, alignment: 4, 
+      stack-id: default, callee-saved-register: '$ra', callee-saved-restored: true, 
+      debug-info-variable: '', debug-info-expression: '', debug-info-location: '' }
+callSites:
+  - { bb: 0, offset: 6, fwdArgRegs: [] }
+body:             |
+  bb.0.entry:
+    liveins: $ra
+  
+    $sp = ADDiu $sp, -24
+    CFI_INSTRUCTION def_cfa_offset 24
+    SW killed $ra, $sp, 20 :: (store 4 into %stack.0)
+    CFI_INSTRUCTION offset $ra_64, -4
+    renamable $at = LUi target-flags(mips-abs-hi) @pm_power_off, debug-location !17
+    renamable $t9 = LW killed renamable $at, target-flags(mips-abs-lo) @pm_power_off, debug-location !17 :: (dereferenceable load 4 from `i32 ()** bitcast (i32 (...)** @pm_power_off to i32 ()**)`)
+    JALRPseudo $t9, csr_o32_fp64, implicit-def dead $ra, implicit-def $sp, implicit-def dead $v0, debug-location !17
+    $ra = LW $sp, 20, debug-location !17 :: (load 4 from %stack.0)
+    $sp = ADDiu $sp, 24
+    PseudoReturn undef $ra, implicit undef $v0, debug-location !17
+
+...