[llvm] r318801 - [Hexagon] Make sure that RDF does not remove EH_LABELs

[Krzysztof Parzyszek via llvm-commits]

Author: kparzysz
Date: Tue Nov 21 13:05:51 2017
New Revision: 318801

URL: http://llvm.org/viewvc/llvm-project?rev=318801&view=rev
Log:
[Hexagon] Make sure that RDF does not remove EH_LABELs

Since EH_LABELs (and other labels) no longer have "side-effects", they
should be checked for separately.

Added:
    llvm/trunk/test/CodeGen/Hexagon/rdf-ehlabel-live.mir
Modified:
    llvm/trunk/lib/Target/Hexagon/RDFDeadCode.cpp

Modified: llvm/trunk/lib/Target/Hexagon/RDFDeadCode.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/Hexagon/RDFDeadCode.cpp?rev=318801&r1=318800&r2=318801&view=diff
==============================================================================
--- llvm/trunk/lib/Target/Hexagon/RDFDeadCode.cpp (original)
+++ llvm/trunk/lib/Target/Hexagon/RDFDeadCode.cpp Tue Nov 21 13:05:51 2017
@@ -58,7 +58,8 @@ private:
 bool DeadCodeElimination::isLiveInstr(const MachineInstr *MI) const {
   if (MI->mayStore() || MI->isBranch() || MI->isCall() || MI->isReturn())
     return true;
-  if (MI->hasOrderedMemoryRef() || MI->hasUnmodeledSideEffects())
+  if (MI->hasOrderedMemoryRef() || MI->hasUnmodeledSideEffects() ||
+      MI->isPosition())
     return true;
   if (MI->isPHI())
     return false;

Added: llvm/trunk/test/CodeGen/Hexagon/rdf-ehlabel-live.mir
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/Hexagon/rdf-ehlabel-live.mir?rev=318801&view=auto
==============================================================================
--- llvm/trunk/test/CodeGen/Hexagon/rdf-ehlabel-live.mir (added)
+++ llvm/trunk/test/CodeGen/Hexagon/rdf-ehlabel-live.mir Tue Nov 21 13:05:51 2017
@@ -0,0 +1,17 @@
+# RUN: llc -march=hexagon -run-pass hexagon-rdf-opt -o - %s | FileCheck %s
+
+# Check that EH_LABELs are not removed as dead (since they are no longer
+# marked as having side-effects):
+# CHECK-LABEL: fred
+# CHECK: EH_LABEL
+
+---
+name: fred
+tracksRegLiveness: true
+
+body: |
+  bb.0:
+    %r0 = A2_tfrsi 0
+    EH_LABEL 0
+...
+