[ThinLTO] Don't convert functions to declarations if `force-import-all` is enabled (#134541)
On one hand, we intend to force import all functions when the option is
enabled.
On the other hand, we currently drop definitions of some functions and
convert
them to declarations, which contradicts this intent.
With this PR, functions will no longer be converted to declarations when
`force-import-all` is enabled.
diff --git a/llvm/lib/LTO/LTO.cpp b/llvm/lib/LTO/LTO.cpp
index 97d23fe..4b6a87e 100644
--- a/llvm/lib/LTO/LTO.cpp
+++ b/llvm/lib/LTO/LTO.cpp
@@ -75,6 +75,8 @@
extern cl::opt<bool> CodeGenDataThinLTOTwoRounds;
+extern cl::opt<bool> ForceImportAll;
+
namespace llvm {
/// Enable global value internalization in LTO.
cl::opt<bool> EnableLTOInternalization(
@@ -406,8 +408,11 @@
Visibility = S->getVisibility();
}
// Alias and aliasee can't be turned into available_externally.
+ // When force-import-all is used, it indicates that object linking is not
+ // supported by the target. In this case, we can't change the linkage as
+ // well in case the global is converted to declaration.
else if (!isa<AliasSummary>(S.get()) &&
- !GlobalInvolvedWithAlias.count(S.get()))
+ !GlobalInvolvedWithAlias.count(S.get()) && !ForceImportAll)
S->setLinkage(GlobalValue::AvailableExternallyLinkage);
// For ELF, set visibility to the computed visibility from summaries. We
diff --git a/llvm/lib/Transforms/IPO/FunctionImport.cpp b/llvm/lib/Transforms/IPO/FunctionImport.cpp
index f1dce5d..12da7f5 100644
--- a/llvm/lib/Transforms/IPO/FunctionImport.cpp
+++ b/llvm/lib/Transforms/IPO/FunctionImport.cpp
@@ -71,6 +71,10 @@
STATISTIC(NumDeadSymbols, "Number of dead stripped symbols in index");
STATISTIC(NumLiveSymbols, "Number of live symbols in index");
+cl::opt<bool>
+ ForceImportAll("force-import-all", cl::init(false), cl::Hidden,
+ cl::desc("Import functions with noinline attribute"));
+
/// Limit on instruction count of imported functions.
static cl::opt<unsigned> ImportInstrLimit(
"import-instr-limit", cl::init(100), cl::Hidden, cl::value_desc("N"),
@@ -80,10 +84,6 @@
"import-cutoff", cl::init(-1), cl::Hidden, cl::value_desc("N"),
cl::desc("Only import first N functions if N>=0 (default -1)"));
-static cl::opt<bool>
- ForceImportAll("force-import-all", cl::init(false), cl::Hidden,
- cl::desc("Import functions with noinline attribute"));
-
static cl::opt<float>
ImportInstrFactor("import-instr-evolution-factor", cl::init(0.7),
cl::Hidden, cl::value_desc("x"),
diff --git a/llvm/test/ThinLTO/AMDGPU/Inputs/in-f1.ll b/llvm/test/ThinLTO/AMDGPU/Inputs/in-f1.ll
new file mode 100644
index 0000000..84fbd66
--- /dev/null
+++ b/llvm/test/ThinLTO/AMDGPU/Inputs/in-f1.ll
@@ -0,0 +1,13 @@
+define void @f1(ptr %v) #0 {
+entry:
+ call void @weak_common(ptr %v)
+ ret void
+}
+
+define weak hidden void @weak_common(ptr %v) #0 {
+entry:
+ store i32 12345, ptr %v
+ ret void
+}
+
+attributes #0 = { noinline }
diff --git a/llvm/test/ThinLTO/AMDGPU/force-import-all.ll b/llvm/test/ThinLTO/AMDGPU/force-import-all.ll
new file mode 100644
index 0000000..829fc51
--- /dev/null
+++ b/llvm/test/ThinLTO/AMDGPU/force-import-all.ll
@@ -0,0 +1,27 @@
+; RUN: opt -mtriple=amdgcn-amd-amdhsa -module-summary %s -o %t.main.bc
+; RUN: opt -mtriple=amdgcn-amd-amdhsa -module-summary %p/Inputs/in-f1.ll -o %t.in.bc
+; RUN: llvm-lto -thinlto-action=run -force-import-all %t.main.bc %t.in.bc --thinlto-save-temps=%t.2.
+; RUN: llvm-dis %t.2.0.3.imported.bc -o - | FileCheck --check-prefix=MOD1 %s
+; RUN: llvm-dis %t.2.1.3.imported.bc -o - | FileCheck --check-prefix=MOD2 %s
+
+define void @f0(ptr %p) #0 {
+entry:
+ call void @f1(ptr %p)
+ ret void
+}
+
+define weak hidden void @weak_common(ptr %v) #0 {
+entry:
+ store i32 12345, ptr %v
+ ret void
+}
+
+declare void @f1(ptr)
+
+attributes #0 = { noinline }
+
+; MOD1: define weak hidden void @weak_common
+; MOD1: define available_externally void @f1
+
+; MOD2: define void @f1
+; MOD2: define weak hidden void @weak_common
diff --git a/llvm/test/ThinLTO/AMDGPU/lit.local.cfg b/llvm/test/ThinLTO/AMDGPU/lit.local.cfg
new file mode 100644
index 0000000..7c49242
--- /dev/null
+++ b/llvm/test/ThinLTO/AMDGPU/lit.local.cfg
@@ -0,0 +1,2 @@
+if not "AMDGPU" in config.root.targets:
+ config.unsupported = True
