[SystemZ] Recognize mnop-mcount in backend

With -pg -mfentry -mnop-mcount, a nop is emitted instead of the call to
fentry.

Review: Ulrich Weigand
https://reviews.llvm.org/D67765

llvm-svn: 372950

2 files changed, 37 insertions, 0 deletions

diff --git a/llvm/test/CodeGen/SystemZ/mnop-mcount-01.ll b/llvm/test/CodeGen/SystemZ/mnop-mcount-01.ll
new file mode 100644
index 00000000000..38f1db537b5
--- /dev/null
+++ b/llvm/test/CodeGen/SystemZ/mnop-mcount-01.ll
@@ -0,0 +1,26 @@
+; RUN: llc %s -mtriple=s390x-linux-gnu -mcpu=z10 -o - -verify-machineinstrs \
+; RUN:   | FileCheck %s
+
+define void @test1() #0 {
+entry:
+  ret void
+
+; CHECK-LABEL: @test1
+; CHECK: brasl %r0, __fentry__
+; CHECK-NOT: brcl 0, .Ltmp0
+; CHECK: br %r14
+}
+
+define void @test2() #1 {
+entry:
+  ret void
+
+; CHECK-LABEL: @test2
+; CHECK-NOT: brasl %r0, __fentry__
+; CHECK: brcl 0, .Ltmp0
+; CHECK: br %r14
+}
+
+attributes #0 = { "fentry-call"="true" }
+attributes #1 = { "fentry-call"="true" "mnop-mcount"="true" }
+
diff --git a/llvm/test/CodeGen/SystemZ/mnop-mcount-02.ll b/llvm/test/CodeGen/SystemZ/mnop-mcount-02.ll
new file mode 100644
index 00000000000..19b1724d16a
--- /dev/null
+++ b/llvm/test/CodeGen/SystemZ/mnop-mcount-02.ll
@@ -0,0 +1,11 @@
+; RUN: not llc %s -mtriple=s390x-linux-gnu -o - 2>&1 | FileCheck %s
+;
+; CHECK: LLVM ERROR: mnop-mcount only supported with fentry-call
+
+define void @test1() #0 {
+entry:
+  ret void
+}
+
+attributes #0 = { "instrument-function-entry-inlined"="mcount" "mnop-mcount"="true" }
+