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, 35 insertions, 0 deletions

diff --git a/llvm/test/Transforms/LowerBitSets/function.ll b/llvm/test/Transforms/LowerBitSets/function.ll
new file mode 100644
index 00000000000..0aa947e5a2d
--- /dev/null
+++ b/llvm/test/Transforms/LowerBitSets/function.ll
@@ -0,0 +1,35 @@
+; RUN: opt -S -lowerbitsets < %s | FileCheck %s
+
+; Tests that we correctly create a jump table for bitsets containing 2 or more
+; functions.
+
+target triple = "x86_64-unknown-linux-gnu"
+target datalayout = "e-p:64:64"
+
+; CHECK: @[[JT:.*]] = private constant [2 x <{ i8, i32, i8, i8, i8 }>] [<{ i8, i32, i8, i8, i8 }> <{ i8 -23, i32 trunc (i64 sub (i64 sub (i64 ptrtoint (void ()* @[[FNAME:.*]] to i64), i64 ptrtoint ([2 x <{ i8, i32, i8, i8, i8 }>]* @[[JT]] to i64)), i64 5) to i32), i8 -52, i8 -52, i8 -52 }>, <{ i8, i32, i8, i8, i8 }> <{ i8 -23, i32 trunc (i64 sub (i64 sub (i64 ptrtoint (void ()* @[[GNAME:.*]] to i64), i64 ptrtoint ([2 x <{ i8, i32, i8, i8, i8 }>]* @[[JT]] to i64)), i64 13) to i32), i8 -52, i8 -52, i8 -52 }>], section ".text"
+
+; CHECK: @f = alias bitcast ([2 x <{ i8, i32, i8, i8, i8 }>]* @[[JT]] to void ()*)
+; CHECK: @g = alias bitcast (<{ i8, i32, i8, i8, i8 }>* getelementptr inbounds ([2 x <{ i8, i32, i8, i8, i8 }>], [2 x <{ i8, i32, i8, i8, i8 }>]* @[[JT]], i64 0, i64 1) to void ()*)
+
+; CHECK: define private void @[[FNAME]]() {
+define void @f() {
+  ret void
+}
+
+; CHECK: define private void @[[GNAME]]() {
+define void @g() {
+  ret void
+}
+
+!0 = !{!"bitset1", void ()* @f, i32 0}
+!1 = !{!"bitset1", void ()* @g, i32 0}
+
+!llvm.bitsets = !{ !0, !1 }
+
+declare i1 @llvm.bitset.test(i8* %ptr, metadata %bitset) nounwind readnone
+
+define i1 @foo(i8* %p) {
+  ; CHECK: sub i64 {{.*}}, ptrtoint ([2 x <{ i8, i32, i8, i8, i8 }>]* @[[JT]] to i64)
+  %x = call i1 @llvm.bitset.test(i8* %p, metadata !"bitset1")
+  ret i1 %x
+}