[llvm] [TableGen] Use MapVector to remove non-determinism (PR #79411)

[via llvm-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-llvm-selectiondag

Author: Wang Pengcheng (wangpc-pp)

<details>
<summary>Changes</summary>

This fixes found non-determinism when `LLVM_REVERSE_ITERATION`
option is `ON`.


---
Full diff: https://github.com/llvm/llvm-project/pull/79411.diff


2 Files Affected:

- (modified) llvm/test/TableGen/address-space-patfrags.td (+2-2) 
- (modified) llvm/utils/TableGen/DAGISelMatcherEmitter.cpp (+2-1) 


``````````diff
diff --git a/llvm/test/TableGen/address-space-patfrags.td b/llvm/test/TableGen/address-space-patfrags.td
index 4aec6ea7e0eae86..46050a70720fbe1 100644
--- a/llvm/test/TableGen/address-space-patfrags.td
+++ b/llvm/test/TableGen/address-space-patfrags.td
@@ -46,7 +46,7 @@ def inst_d : Instruction {
   let InOperandList = (ins GPR32:$src0, GPR32:$src1);
 }
 
-// SDAG: case 1: {
+// SDAG: case 0: {
 // SDAG-NEXT: // Predicate_pat_frag_b
 // SDAG-NEXT: // Predicate_truncstorei16_addrspace
 // SDAG-NEXT: SDNode *N = Node;
@@ -69,7 +69,7 @@ def : Pat <
 >;
 
 
-// SDAG: case 6: {
+// SDAG: case 4: {
 // SDAG: // Predicate_pat_frag_a
 // SDAG-NEXT: SDNode *N = Node;
 // SDAG-NEXT: (void)N;
diff --git a/llvm/utils/TableGen/DAGISelMatcherEmitter.cpp b/llvm/utils/TableGen/DAGISelMatcherEmitter.cpp
index 455183987b7b27b..50156d34528c153 100644
--- a/llvm/utils/TableGen/DAGISelMatcherEmitter.cpp
+++ b/llvm/utils/TableGen/DAGISelMatcherEmitter.cpp
@@ -57,7 +57,8 @@ class MatcherTableEmitter {
 
   // We de-duplicate the predicates by code string, and use this map to track
   // all the patterns with "identical" predicates.
-  StringMap<TinyPtrVector<TreePattern *>> NodePredicatesByCodeToRun;
+  MapVector<std::string, TinyPtrVector<TreePattern *>, StringMap<unsigned>>
+      NodePredicatesByCodeToRun;
 
   std::vector<std::string> PatternPredicates;
 

``````````

</details>


https://github.com/llvm/llvm-project/pull/79411