Adding a pass - RewritePNaClLibraryCalls, that replaces known library calls with stable bitcode int…

test/Transforms/NaCl/rewrite-setlongjmp-calls.ll

+; RUN: opt < %s -rewrite-pnacl-library-calls -S | FileCheck %s
+; Test the RewritePNaClLibraryCalls pass
+
+declare i32 @setjmp(i64*)
+declare void @longjmp(i64*, i32)
+
+define i32 @call_setjmp(i64* %arg) {
+; CHECK-NOT: call i32 @setjmp
+; CHECK: %jmp_buf_i8 = bitcast i64* %arg to i8*
+; CHECK-NEXT: %val = call i32 @llvm.nacl.setjmp(i8* %jmp_buf_i8)
+  %val = call i32 @setjmp(i64* %arg)
+  ret i32 %val
+}
+
+define void @call_longjmp(i64* %arg, i32 %num) {
+; CHECK-NOT: call void @longjmp
+; CHECK: %jmp_buf_i8 = bitcast i64* %arg to i8*
+; CHECK-NEXT: call void @llvm.nacl.longjmp(i8* %jmp_buf_i8, i32 %num)
+  call void @longjmp(i64* %arg, i32 %num)
+  ret void
+}
+
+define i32 @takeaddr_longjmp(i64* %arg, i32 %num) {
+  %fp = alloca void (i64*, i32)*, align 8
+; CHECK-NOT: store void (i64*, i32)* @longjmp
+; CHECK: store void (i64*, i32)* @__nacl_wrap_longjmp, void (i64*, i32)** %fp
+  store void (i64*, i32)* @longjmp, void (i64*, i32)** %fp, align 8
+  ret i32 7
+}
+
+; A more complex example with a number of calls in several BBs
+define void @multiple_calls(i64* %arg, i32 %num) {
+entryblock:
+; CHECK: entryblock
+; CHECK: bitcast
+; CHECK-NEXT: call void @llvm.nacl.longjmp
+  call void @longjmp(i64* %arg, i32 %num)
+  br label %block1
+block1:
+; CHECK: block1
+; CHECK: bitcast
+; CHECK-NEXT: call void @llvm.nacl.longjmp
+  call void @longjmp(i64* %arg, i32 %num)
+; CHECK: call i32 @llvm.nacl.setjmp
+  %val = call i32 @setjmp(i64* %arg)
+  %num2 = add i32 %val, %num
+; CHECK: bitcast
+; CHECK-NEXT: call void @llvm.nacl.longjmp
+  call void @longjmp(i64* %arg, i32 %num2)
+  br label %exitblock
+exitblock:
+  %num3 = add i32 %num, %num
+  call void @longjmp(i64* %arg, i32 %num3)
+  %num4 = add i32 %num, %num3
+; CHECK: bitcast
+; CHECK-NEXT: call void @llvm.nacl.longjmp
+  call void @longjmp(i64* %arg, i32 %num4)
+  ret void
+}
+
+; CHECK: declare i32 @llvm.nacl.setjmp(i8*)
+; CHECK: declare void @llvm.nacl.longjmp(i8*, i32)
+
+; CHECK:      define private void @__nacl_wrap_longjmp(i64* %env, i32 %val) {
+; CHECK-NEXT:   entry:
+; CHECK-NEXT:   %jmp_buf_i8 = bitcast i64* %env to i8*
+; CHECK-NEXT:   call void @llvm.nacl.longjmp(i8* %jmp_buf_i8, i32 %val)
+; CHECK-NEXT:   ret void
+; CHECK-NEXT: }
+