[ThinLTO] Internalize readonly globals
An attempt to recommit r346584 after failure on OSX build bot.
Fixed cache key computation in ThinLTOCodeGenerator and added
test case
llvm-svn: 347033
diff --git a/llvm/test/ThinLTO/X86/index-const-prop2.ll b/llvm/test/ThinLTO/X86/index-const-prop2.ll
new file mode 100644
index 0000000..d6c8ec8
--- /dev/null
+++ b/llvm/test/ThinLTO/X86/index-const-prop2.ll
@@ -0,0 +1,59 @@
+; Check constant propagation in thinlto combined summary. This allows us to do 2 things:
+; 1. Internalize global definition which is not used externally if all accesses to it are read-only
+; 2. Make a local copy of internal definition if all accesses to it are readonly. This allows constant
+; folding it during optimziation phase.
+; RUN: opt -module-summary %s -o %t1.bc
+; RUN: opt -module-summary %p/Inputs/index-const-prop.ll -o %t2.bc
+; RUN: llvm-lto2 run %t1.bc %t2.bc -save-temps \
+; RUN: -r=%t2.bc,foo,pl \
+; RUN: -r=%t2.bc,bar,pl \
+; RUN: -r=%t2.bc,baz,pl \
+; RUN: -r=%t2.bc,rand, \
+; RUN: -r=%t2.bc,gBar,pl \
+; RUN: -r=%t1.bc,main,plx \
+; RUN: -r=%t1.bc,foo, \
+; RUN: -r=%t1.bc,bar, \
+; RUN: -r=%t1.bc,gBar, \
+; RUN: -o %t3
+; RUN: llvm-dis %t3.1.3.import.bc -o - | FileCheck %s --check-prefix=IMPORT
+; RUN: llvm-dis %t3.1.5.precodegen.bc -o - | FileCheck %s --check-prefix=CODEGEN
+
+; Now check that we won't internalize global (gBar) if it's externally referenced
+; RUN: llvm-lto2 run %t1.bc %t2.bc -save-temps \
+; RUN: -r=%t2.bc,foo,pl \
+; RUN: -r=%t2.bc,bar,pl \
+; RUN: -r=%t2.bc,baz,pl \
+; RUN: -r=%t2.bc,rand, \
+; RUN: -r=%t2.bc,gBar,plx \
+; RUN: -r=%t1.bc,main,plx \
+; RUN: -r=%t1.bc,foo, \
+; RUN: -r=%t1.bc,bar, \
+; RUN: -r=%t1.bc,gBar, \
+; RUN: -o %t3
+; RUN: llvm-dis %t3.1.3.import.bc -o - | FileCheck %s --check-prefix=IMPORT2
+
+; IMPORT: @gFoo.llvm.0 = internal unnamed_addr global i32 1, align 4
+; IMPORT-NEXT: @gBar = internal local_unnamed_addr global i32 2, align 4
+; IMPORT: !DICompileUnit({{.*}}, globals: !{{[0-9]+}})
+
+; CODEGEN: i32 @main()
+; CODEGEN-NEXT: ret i32 3
+
+; IMPORT2: @gBar = available_externally dso_local local_unnamed_addr global i32 2, align 4
+
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-pc-linux-gnu"
+
+; We should be able to link external definition of gBar to its declaration
+@gBar = external global i32
+
+define i32 @main() local_unnamed_addr {
+ %call = tail call i32 bitcast (i32 (...)* @foo to i32 ()*)()
+ %call1 = tail call i32 bitcast (i32 (...)* @bar to i32 ()*)()
+ %add = add nsw i32 %call1, %call
+ ret i32 %add
+}
+
+declare i32 @foo(...) local_unnamed_addr
+
+declare i32 @bar(...) local_unnamed_addr