Add to the split module utility an SCC based method which allows not to globalize any local variables.

    
    Summary:
    Currently llvm::SplitModule as the first step globalizes all local objects, which might not be desirable in some scenarios.
    This change adds a new flag to llvm::SplitModule that uses SCC approach to search for a balanced partition without the need to externalize symbols.
    Such partition might not be possible or fully balanced for a given number of partitions, and is a function of the module properties (global/local dependencies within the module).
    
    Joint development Tobias Edler von Koch (tobias@codeaurora.org) and Sergei Larin (slarin@codeaurora.org)
    
    Subscribers: llvm-commits, joker.eph
    
    Differential Revision: http://reviews.llvm.org/D16124

llvm-svn: 258083

1 files changed, 48 insertions, 0 deletions

diff --git a/llvm/test/tools/llvm-split/scc-callchain.ll b/llvm/test/tools/llvm-split/scc-callchain.ll
new file mode 100644
index 00000000000..953a0244ae7
--- /dev/null
+++ b/llvm/test/tools/llvm-split/scc-callchain.ll
@@ -0,0 +1,48 @@
+; All of the functions in this module must end up
+; in the same partition.
+
+; RUN: llvm-split -j=2 -preserve-locals -o %t %s
+; RUN: llvm-dis -o - %t0 | FileCheck --check-prefix=CHECK1 %s
+; RUN: llvm-dis -o - %t1 | FileCheck --check-prefix=CHECK0 %s
+
+; CHECK0: declare i32 @funInternal0
+; CHECK0: declare i32 @funInternal1
+; CHECK0: declare i32 @funInternal2
+; CHECK0: declare i32 @funExternal
+
+; All functions are in the same file.
+; Local functions are still local.
+; CHECK1: define internal i32 @funInternal0
+; CHECK1: define internal i32 @funInternal1
+; CHECK1: define internal i32 @funInternal2
+; CHECK1: define i32 @funExternal
+; CHECK1: define i32 @funExternal2
+
+define internal i32 @funInternal0() {
+entry:
+  ret i32 0
+}
+
+define internal i32 @funInternal1() {
+entry:
+  %x = call i32 @funInternal0()
+  ret i32 %x
+}
+
+define internal i32 @funInternal2() {
+entry:
+  %x = call i32 @funInternal1()
+  ret i32 %x
+}
+
+define i32 @funExternal() {
+entry:
+  %x = call i32 @funInternal2()
+  ret i32 %x
+}
+
+define i32 @funExternal2() {
+entry:
+  %x = call i32 @funInternal0()
+  ret i32 %x
+}