Enable IPConstantPropagation to work with abstract call sites
This modification of the currently unused inter-procedural constant
propagation pass (IPConstantPropagation) shows how abstract call sites
enable optimization of callback calls alongside direct and indirect
calls. Through minimal changes, mostly dealing with the partial mapping
of callbacks, inter-procedural constant propagation was enabled for
callbacks, e.g., OpenMP runtime calls or pthreads_create.
Differential Revision: https://reviews.llvm.org/D56447
llvm-svn: 351628
diff --git a/llvm/test/Transforms/IPConstantProp/pthreads.ll b/llvm/test/Transforms/IPConstantProp/pthreads.ll
new file mode 100644
index 0000000..0af2c16
--- /dev/null
+++ b/llvm/test/Transforms/IPConstantProp/pthreads.ll
@@ -0,0 +1,49 @@
+; RUN: opt -ipconstprop -S < %s | FileCheck %s
+;
+; #include <pthread.h>
+;
+; void *GlobalVPtr;
+;
+; static void *foo(void *arg) { return arg; }
+; static void *bar(void *arg) { return arg; }
+;
+; int main() {
+; pthread_t thread;
+; pthread_create(&thread, NULL, foo, NULL);
+; pthread_create(&thread, NULL, bar, &GlobalVPtr);
+; return 0;
+; }
+;
+; Verify the constant values NULL and &GlobalVPtr are propagated into foo and
+; bar, respectively.
+;
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+
+%union.pthread_attr_t = type { i64, [48 x i8] }
+
+@GlobalVPtr = common dso_local global i8* null, align 8
+
+define dso_local i32 @main() {
+entry:
+ %thread = alloca i64, align 8
+ %call = call i32 @pthread_create(i64* nonnull %thread, %union.pthread_attr_t* null, i8* (i8*)* nonnull @foo, i8* null)
+ %call1 = call i32 @pthread_create(i64* nonnull %thread, %union.pthread_attr_t* null, i8* (i8*)* nonnull @bar, i8* bitcast (i8** @GlobalVPtr to i8*))
+ ret i32 0
+}
+
+declare !callback !0 dso_local i32 @pthread_create(i64*, %union.pthread_attr_t*, i8* (i8*)*, i8*)
+
+define internal i8* @foo(i8* %arg) {
+entry:
+; CHECK: ret i8* null
+ ret i8* %arg
+}
+
+define internal i8* @bar(i8* %arg) {
+entry:
+; CHECK: ret i8* bitcast (i8** @GlobalVPtr to i8*)
+ ret i8* %arg
+}
+
+!1 = !{i64 2, i64 3, i1 false}
+!0 = !{!1}