[llvm] d933c89 - [GVN] Simplify presplit coroutine handling. NFC.

[Jay Foad via llvm-commits]

Author: Jay Foad
Date: 2023-05-19T15:46:29+01:00
New Revision: d933c895348b79a28cdb9e330e0ee5146bac5adf

URL: https://github.com/llvm/llvm-project/commit/d933c895348b79a28cdb9e330e0ee5146bac5adf
DIFF: https://github.com/llvm/llvm-project/commit/d933c895348b79a28cdb9e330e0ee5146bac5adf.diff

LOG: [GVN] Simplify presplit coroutine handling. NFC.

Added: 
    

Modified: 
    llvm/lib/Transforms/Scalar/GVN.cpp

Removed: 
    


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diff  --git a/llvm/lib/Transforms/Scalar/GVN.cpp b/llvm/lib/Transforms/Scalar/GVN.cpp
index 3f94cae876a9..3e30f1582715 100644
--- a/llvm/lib/Transforms/Scalar/GVN.cpp
+++ b/llvm/lib/Transforms/Scalar/GVN.cpp
@@ -461,30 +461,26 @@ void GVNPass::ValueTable::add(Value *V, uint32_t num) {
 }
 
 uint32_t GVNPass::ValueTable::lookupOrAddCall(CallInst *C) {
-  if (AA->doesNotAccessMemory(C) &&
-      // FIXME: Currently the calls which may access the thread id may
-      // be considered as not accessing the memory. But this is
-      // problematic for coroutines, since coroutines may resume in a
-      // 
diff erent thread. So we disable the optimization here for the
-      // correctness. However, it may block many other correct
-      // optimizations. Revert this one when we detect the memory
-      // accessing kind more precisely.
-      !C->getFunction()->isPresplitCoroutine()) {
+  // FIXME: Currently the calls which may access the thread id may
+  // be considered as not accessing the memory. But this is
+  // problematic for coroutines, since coroutines may resume in a
+  // 
diff erent thread. So we disable the optimization here for the
+  // correctness. However, it may block many other correct
+  // optimizations. Revert this one when we detect the memory
+  // accessing kind more precisely.
+  if (C->getFunction()->isPresplitCoroutine()) {
+    valueNumbering[C] = nextValueNumber;
+    return nextValueNumber++;
+  }
+
+  if (AA->doesNotAccessMemory(C)) {
     Expression exp = createExpr(C);
     uint32_t e = assignExpNewValueNum(exp).first;
     valueNumbering[C] = e;
     return e;
   }
 
-  if (MD && AA->onlyReadsMemory(C) &&
-      // FIXME: Currently the calls which may access the thread id may
-      // be considered as not accessing the memory. But this is
-      // problematic for coroutines, since coroutines may resume in a
-      // 
diff erent thread. So we disable the optimization here for the
-      // correctness. However, it may block many other correct
-      // optimizations. Revert this one when we detect the memory
-      // accessing kind more precisely.
-      !C->getFunction()->isPresplitCoroutine()) {
+  if (MD && AA->onlyReadsMemory(C)) {
     Expression exp = createExpr(C);
     auto ValNum = assignExpNewValueNum(exp);
     if (ValNum.second) {