[llvm] af9a452 - [llvm][codegen] Fix non-determinism in StackFrameLayoutAnalysisPass output

[Paul Kirth via llvm-commits]

Author: Paul Kirth
Date: 2023-01-19T20:04:14Z
New Revision: af9a452e57554c2c5e876986e33c2a75314259e8

URL: https://github.com/llvm/llvm-project/commit/af9a452e57554c2c5e876986e33c2a75314259e8
DIFF: https://github.com/llvm/llvm-project/commit/af9a452e57554c2c5e876986e33c2a75314259e8.diff

LOG: [llvm][codegen] Fix non-determinism in StackFrameLayoutAnalysisPass output

We were iterating over a SmallPtrSet when outputting slot variables.
This is still correct but made the test fail under reverse iteration.
This patch replaces the SmallPtrSet with a SmallVector.

Also remove the "Stack Frame Layout" lines from arm64-opt-remarks-lazy-bfi test,
since those also break under reverse iteration.

Reviewed By: nickdesaulniers

Differential Revision: https://reviews.llvm.org/D142127

Added: 
    

Modified: 
    llvm/lib/CodeGen/StackFrameLayoutAnalysisPass.cpp
    llvm/test/CodeGen/AArch64/arm64-opt-remarks-lazy-bfi.ll

Removed: 
    


################################################################################
diff  --git a/llvm/lib/CodeGen/StackFrameLayoutAnalysisPass.cpp b/llvm/lib/CodeGen/StackFrameLayoutAnalysisPass.cpp
index ddac093423fa6..3a48dd5b0a034 100644
--- a/llvm/lib/CodeGen/StackFrameLayoutAnalysisPass.cpp
+++ b/llvm/lib/CodeGen/StackFrameLayoutAnalysisPass.cpp
@@ -16,6 +16,7 @@
 //
 //===----------------------------------------------------------------------===//
 
+#include "llvm/ADT/SetVector.h"
 #include "llvm/Analysis/OptimizationRemarkEmitter.h"
 #include "llvm/CodeGen/MachineFrameInfo.h"
 #include "llvm/CodeGen/MachineFunction.h"
@@ -45,8 +46,7 @@ namespace {
 /// MachineFunction.
 ///
 struct StackFrameLayoutAnalysisPass : public MachineFunctionPass {
-  using SlotDbgMap =
-      SmallDenseMap<int, SmallPtrSet<const DILocalVariable *, 4>>;
+  using SlotDbgMap = SmallDenseMap<int, SetVector<const DILocalVariable *>>;
   static char ID;
 
   enum SlotType {
@@ -180,18 +180,15 @@ struct StackFrameLayoutAnalysisPass : public MachineFunctionPass {
                       << MFI.getStackProtectorIndex() << "\n");
 
     std::vector<SlotData> SlotInfo;
-    SmallDenseMap<int, int> SlotOffsetMap;
 
     const unsigned int NumObj = MFI.getNumObjects();
     SlotInfo.reserve(NumObj);
-    SlotOffsetMap.reserve(NumObj);
     // initialize slot info
     for (int Idx = MFI.getObjectIndexBegin(), EndIdx = MFI.getObjectIndexEnd();
          Idx != EndIdx; ++Idx) {
       if (MFI.isDeadObjectIndex(Idx))
         continue;
-      auto &Inserted = SlotInfo.emplace_back(MFI, ValOffset, Idx);
-      SlotOffsetMap[Inserted.Slot] = Inserted.Offset;
+      SlotInfo.emplace_back(MFI, ValOffset, Idx);
     }
 
     // sort the ordering, to match the actual layout in memory

diff  --git a/llvm/test/CodeGen/AArch64/arm64-opt-remarks-lazy-bfi.ll b/llvm/test/CodeGen/AArch64/arm64-opt-remarks-lazy-bfi.ll
index 9295897dd22d3..2b826b208f551 100644
--- a/llvm/test/CodeGen/AArch64/arm64-opt-remarks-lazy-bfi.ll
+++ b/llvm/test/CodeGen/AArch64/arm64-opt-remarks-lazy-bfi.ll
@@ -38,13 +38,7 @@
 ; HOTNESS-NEXT: Freeing Pass 'Insert CFI remember/restore state instructions' on Function 'empty_func'
 ; HOTNESS-NEXT: Executing Pass 'Verify generated machine code'
 ; HOTNESS-NEXT: Freeing Pass 'Verify generated machine code'
-; HOTNESS-NEXT: Executing Pass 'Lazy Machine Block Frequency Analysis'
-; HOTNESS-NEXT: Executing Pass 'Machine Optimization Remark Emitter'
-; HOTNESS:      Executing Pass 'Stack Frame Layout Analysis'
-; HOTNESS-NEXT: Freeing Pass 'Machine Optimization Remark Emitter'
-; HOTNESS-NEXT: Freeing Pass 'Lazy Machine Block Frequency Analysis'
-; HOTNESS-NEXT: Freeing Pass 'Stack Frame Layout Analysis'
-; HOTNESS-NEXT: Executing Pass 'Unpack machine instruction bundles'
+; HOTNESS:      Executing Pass 'Unpack machine instruction bundles'
 ; HOTNESS-NEXT: Freeing Pass 'Unpack machine instruction bundles'
 ; HOTNESS-NEXT: Executing Pass 'Verify generated machine code'
 ; HOTNESS-NEXT: Freeing Pass 'Verify generated machine code'
@@ -69,13 +63,7 @@
 ; NO_HOTNESS-NEXT: Freeing Pass 'Insert CFI remember/restore state instructions' on Function 'empty_func'
 ; NO_HOTNESS-NEXT: Executing Pass 'Verify generated machine code'
 ; NO_HOTNESS-NEXT: Freeing Pass 'Verify generated machine code'
-; NO_HOTNESS-NEXT: Executing Pass 'Lazy Machine Block Frequency Analysis'
-; NO_HOTNESS-NEXT: Executing Pass 'Machine Optimization Remark Emitter'
-; NO_HOTNESS:      Executing Pass 'Stack Frame Layout Analysis'
-; NO_HOTNESS-NEXT: Freeing Pass 'Machine Optimization Remark Emitter'
-; NO_HOTNESS-NEXT: Freeing Pass 'Lazy Machine Block Frequency Analysis'
-; NO_HOTNESS-NEXT: Freeing Pass 'Stack Frame Layout Analysis'
-; NO_HOTNESS-NEXT: Executing Pass 'Unpack machine instruction bundles'
+; NO_HOTNESS:      Executing Pass 'Unpack machine instruction bundles'
 ; NO_HOTNESS-NEXT: Freeing Pass 'Unpack machine instruction bundles'
 ; NO_HOTNESS-NEXT: Executing Pass 'Verify generated machine code'
 ; NO_HOTNESS-NEXT: Freeing Pass 'Verify generated machine code'