[llvm] 1cbb456 - [GlobalOpt] Fix global to select transform under opaque pointers

[Nikita Popov via llvm-commits]

Author: Nikita Popov
Date: 2022-01-13T11:13:06+01:00
New Revision: 1cbb456123a9e104d2a29c42f021ab537f18397b

URL: https://github.com/llvm/llvm-project/commit/1cbb456123a9e104d2a29c42f021ab537f18397b
DIFF: https://github.com/llvm/llvm-project/commit/1cbb456123a9e104d2a29c42f021ab537f18397b.diff

LOG: [GlobalOpt] Fix global to select transform under opaque pointers

We need to check that the load/store type is also the same, as this
is no longer implicitly checked through the pointer type.

Added: 
    llvm/test/Transforms/GlobalOpt/shrink-global-to-bool-opaque-ptrs.ll

Modified: 
    llvm/lib/Transforms/IPO/GlobalOpt.cpp

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Transforms/IPO/GlobalOpt.cpp b/llvm/lib/Transforms/IPO/GlobalOpt.cpp
index 82800a5ba957..0a39c4a9eb11 100644
--- a/llvm/lib/Transforms/IPO/GlobalOpt.cpp
+++ b/llvm/lib/Transforms/IPO/GlobalOpt.cpp
@@ -1252,9 +1252,12 @@ static bool TryToShrinkGlobalToBoolean(GlobalVariable *GV, Constant *OtherVal) {
 
   // Walk the use list of the global seeing if all the uses are load or store.
   // If there is anything else, bail out.
-  for (User *U : GV->users())
+  for (User *U : GV->users()) {
     if (!isa<LoadInst>(U) && !isa<StoreInst>(U))
       return false;
+    if (getLoadStoreType(U) != GVElType)
+      return false;
+  }
 
   LLVM_DEBUG(dbgs() << "   *** SHRINKING TO BOOL: " << *GV << "\n");
 

diff  --git a/llvm/test/Transforms/GlobalOpt/shrink-global-to-bool-opaque-ptrs.ll b/llvm/test/Transforms/GlobalOpt/shrink-global-to-bool-opaque-ptrs.ll
new file mode 100644
index 000000000000..5d3a35f6474d
--- /dev/null
+++ b/llvm/test/Transforms/GlobalOpt/shrink-global-to-bool-opaque-ptrs.ll
@@ -0,0 +1,64 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt -S -globalopt -opaque-pointers < %s | FileCheck %s
+
+; Make sure we don't try to convert to select if the load/stores don't match
+; the global type.
+
+ at g1 = internal global i64 zeroinitializer
+ at g2 = internal global i64 zeroinitializer
+ at g3 = internal global i64 zeroinitializer
+
+define void @store1() {
+; CHECK-LABEL: @store1(
+; CHECK-NEXT:    store i32 2, ptr @g1, align 4
+; CHECK-NEXT:    ret void
+;
+  store i32 2, ptr @g1
+  ret void
+}
+
+define i32 @load1() {
+; CHECK-LABEL: @load1(
+; CHECK-NEXT:    [[V:%.*]] = load i32, ptr @g1, align 4
+; CHECK-NEXT:    ret i32 [[V]]
+;
+  %v = load i32, ptr @g1
+  ret i32 %v
+}
+
+define void @store2() {
+; CHECK-LABEL: @store2(
+; CHECK-NEXT:    store i64 2, ptr @g2, align 4
+; CHECK-NEXT:    ret void
+;
+  store i64 2, ptr @g2
+  ret void
+}
+
+define i32 @load2() {
+; CHECK-LABEL: @load2(
+; CHECK-NEXT:    [[V:%.*]] = load i32, ptr @g2, align 4
+; CHECK-NEXT:    ret i32 [[V]]
+;
+  %v = load i32, ptr @g2
+  ret i32 %v
+}
+
+define void @store3() {
+; CHECK-LABEL: @store3(
+; CHECK-NEXT:    store i1 true, ptr @g3, align 1
+; CHECK-NEXT:    ret void
+;
+  store i64 2, ptr @g3
+  ret void
+}
+
+define i64 @load3() {
+; CHECK-LABEL: @load3(
+; CHECK-NEXT:    [[V_B:%.*]] = load i1, ptr @g3, align 1
+; CHECK-NEXT:    [[V:%.*]] = select i1 [[V_B]], i64 2, i64 0
+; CHECK-NEXT:    ret i64 [[V]]
+;
+  %v = load i64, ptr @g3
+  ret i64 %v
+}