LowerBitSets: Extend pass to support functions as bitset members.

This change extends the bitset lowering pass to support bitsets that may
contain either functions or global variables. A function bitset is lowered to
a jump table that is laid out before one of the functions in the bitset.

Also add support for non-string bitset identifier names. This allows for
distinct metadata nodes to stand in for names with internal linkage,
as done in D11857.

Differential Revision: http://reviews.llvm.org/D11856

llvm-svn: 247080

1 files changed, 22 insertions, 0 deletions

diff --git a/llvm/test/Transforms/LowerBitSets/function-ext.ll b/llvm/test/Transforms/LowerBitSets/function-ext.ll
new file mode 100644
index 00000000000..2a83bef2f07
--- /dev/null
+++ b/llvm/test/Transforms/LowerBitSets/function-ext.ll
@@ -0,0 +1,22 @@
+; RUN: opt -S -lowerbitsets < %s | FileCheck %s
+
+; Tests that we correctly handle external references, including the case where
+; all functions in a bitset are external references.
+
+target triple = "x86_64-unknown-linux-gnu"
+
+declare void @foo()
+
+; CHECK: @[[JT:.*]] = private constant [1 x <{ i8, i32, i8, i8, i8 }>] [<{ i8, i32, i8, i8, i8 }> <{ i8 -23, i32 trunc (i64 sub (i64 sub (i64 ptrtoint (void ()* @foo to i64), i64 ptrtoint ([1 x <{ i8, i32, i8, i8, i8 }>]* @[[JT]] to i64)), i64 5) to i32), i8 -52, i8 -52, i8 -52 }>], section ".text"
+
+define i1 @bar(i8* %ptr) {
+  ; CHECK: icmp eq i64 {{.*}}, ptrtoint ([1 x <{ i8, i32, i8, i8, i8 }>]* @[[JT]] to i64)
+  %p = call i1 @llvm.bitset.test(i8* %ptr, metadata !"void")
+  ret i1 %p
+}
+
+declare i1 @llvm.bitset.test(i8* %ptr, metadata %bitset) nounwind readnone
+
+!0 = !{!"void", void ()* @foo, i64 0}
+
+!llvm.bitsets = !{!0}