[llvm] e50a8c8 - [GlobalMerge] Ensure that the MustKeepGlobalVariables has all globals from each landingpad clause.
Stefan Pintilie via llvm-commits
llvm-commits at lists.llvm.org
Wed Jun 29 13:55:51 PDT 2022
Author: Stefan Pintilie
Date: 2022-06-29T15:55:47-05:00
New Revision: e50a8c8435e0c80e3b9881f58e335305d1c1e366
URL: https://github.com/llvm/llvm-project/commit/e50a8c8435e0c80e3b9881f58e335305d1c1e366
DIFF: https://github.com/llvm/llvm-project/commit/e50a8c8435e0c80e3b9881f58e335305d1c1e366.diff
LOG: [GlobalMerge] Ensure that the MustKeepGlobalVariables has all globals from each landingpad clause.
The filter clause in the landingpad may not have a GlobalVariable operand.
It may instead have a ConstantArray of operands and each operand within this
ConstantArray should also be checked to see if it is a GlobalVariable.
This patch add the check for the ConstantArray as well as a debug message that
outputs the contents of MustKeepGlobalVariables.
Reviewed By: lei, amyk, scui
Differential Revision: https://reviews.llvm.org/D128287
Added:
llvm/test/Transforms/GlobalMerge/eh-filter.ll
Modified:
llvm/lib/CodeGen/GlobalMerge.cpp
Removed:
################################################################################
diff --git a/llvm/lib/CodeGen/GlobalMerge.cpp b/llvm/lib/CodeGen/GlobalMerge.cpp
index bbd9006a5d8c5..f5833d3b9086f 100644
--- a/llvm/lib/CodeGen/GlobalMerge.cpp
+++ b/llvm/lib/CodeGen/GlobalMerge.cpp
@@ -592,6 +592,13 @@ void GlobalMerge::setMustKeepGlobalVariables(Module &M) {
if (const GlobalVariable *GV =
dyn_cast<GlobalVariable>(U->stripPointerCasts()))
MustKeepGlobalVariables.insert(GV);
+ else if (const ConstantArray *CA = dyn_cast<ConstantArray>(U->stripPointerCasts())) {
+ for (const Use &Elt : CA->operands()) {
+ if (const GlobalVariable *GV =
+ dyn_cast<GlobalVariable>(Elt->stripPointerCasts()))
+ MustKeepGlobalVariables.insert(GV);
+ }
+ }
}
}
}
@@ -609,6 +616,13 @@ bool GlobalMerge::doInitialization(Module &M) {
bool Changed = false;
setMustKeepGlobalVariables(M);
+ LLVM_DEBUG({
+ dbgs() << "Number of GV that must be kept: " <<
+ MustKeepGlobalVariables.size() << "\n";
+ for (auto KeptGV = MustKeepGlobalVariables.begin();
+ KeptGV != MustKeepGlobalVariables.end(); KeptGV++)
+ dbgs() << "Kept: " << **KeptGV << "\n";
+ });
// Grab all non-const globals.
for (auto &GV : M.globals()) {
// Merge is safe for "normal" internal or external globals only
diff --git a/llvm/test/Transforms/GlobalMerge/eh-filter.ll b/llvm/test/Transforms/GlobalMerge/eh-filter.ll
new file mode 100644
index 0000000000000..95b51413e1c26
--- /dev/null
+++ b/llvm/test/Transforms/GlobalMerge/eh-filter.ll
@@ -0,0 +1,69 @@
+; RUN: opt -global-merge -debug-only=global-merge -S -o - %s 2>&1 | FileCheck %s
+
+;; Checks from the debug info.
+; CHECK: Number of GV that must be kept: 5
+; CHECK-NEXT: Kept: @_ZTIi = external constant ptr
+; CHECK-NEXT: Kept: @_ZTIf = external constant ptr
+; CHECK-NEXT: Kept: @_ZTId = external constant ptr
+; CHECK-NEXT: Kept: @_ZTIc = external constant ptr
+; CHECK-NEXT: Kept: @_ZTIPi = external constant ptr
+
+;; Check that the landingpad, catch and filter have not changed.
+; CHECK: %0 = landingpad { ptr, i32 }
+; CHECK-NEXT: catch ptr @_ZTIi
+; CHECK-NEXT: filter [5 x ptr] [ptr @_ZTIi, ptr @_ZTIf, ptr @_ZTId, ptr @_ZTIc, ptr @_ZTIPi]
+
+ at _ZTIi = external constant ptr
+ at _ZTIf = external constant ptr
+ at _ZTId = external constant ptr
+ at _ZTIc = external constant ptr
+ at _ZTIPi = external constant ptr
+
+define noundef signext i32 @_Z6calleri(i32 noundef signext %a) local_unnamed_addr personality ptr @__xlcxx_personality_v1 {
+entry:
+ invoke void @_Z16callee_can_throwi(i32 noundef signext %a)
+ to label %return unwind label %lpad
+
+lpad: ; preds = %entry
+ %0 = landingpad { ptr, i32 }
+ catch ptr @_ZTIi
+ filter [5 x ptr] [ptr @_ZTIi, ptr @_ZTIf, ptr @_ZTId, ptr @_ZTIc, ptr @_ZTIPi]
+ %1 = extractvalue { ptr, i32 } %0, 0
+ %2 = extractvalue { ptr, i32 } %0, 1
+ %3 = tail call i32 @llvm.eh.typeid.for(ptr nonnull @_ZTIi)
+ %matches = icmp eq i32 %2, %3
+ br i1 %matches, label %catch, label %filter.dispatch
+
+filter.dispatch: ; preds = %lpad
+ %ehspec.fails = icmp slt i32 %2, 0
+ br i1 %ehspec.fails, label %ehspec.unexpected, label %eh.resume
+
+ehspec.unexpected: ; preds = %filter.dispatch
+ tail call void @__cxa_call_unexpected(ptr %1)
+ unreachable
+
+catch: ; preds = %lpad
+ %4 = tail call ptr @__cxa_begin_catch(ptr %1)
+ %5 = load i32, ptr %4, align 4
+ tail call void @__cxa_end_catch()
+ br label %return
+
+return: ; preds = %entry, %catch
+ %retval.0 = phi i32 [ %5, %catch ], [ 0, %entry ]
+ ret i32 %retval.0
+
+eh.resume: ; preds = %filter.dispatch
+ resume { ptr, i32 } %0
+}
+
+declare void @_Z16callee_can_throwi(i32 noundef signext) local_unnamed_addr
+
+declare i32 @__xlcxx_personality_v1(...)
+
+declare i32 @llvm.eh.typeid.for(ptr)
+
+declare ptr @__cxa_begin_catch(ptr) local_unnamed_addr
+
+declare void @__cxa_end_catch() local_unnamed_addr
+
+declare void @__cxa_call_unexpected(ptr) local_unnamed_addr
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