Skip BBs without SSA representation in the Constant Propagation phase

In some cases the constant propagation optimization may get the MIR graph
where some of the BBs have no predecessors and do not transformed to the
SSA form. If such BB has operations on constants this may lead to segfault.
This patch adds the condition that will pass the only BBs with SSA.

Change-Id: I816d46b2492c5bd4748f983c3725b4798f9ebd68
Signed-off-by: Alexei Zavjalov <alexei.zavjalov@intel.com>

3 files changed, 33 insertions, 0 deletions

diff --git a/compiler/dex/mir_optimization.cc b/compiler/dex/mir_optimization.cc
index 51419f4..937e258 100644
--- a/compiler/dex/mir_optimization.cc
+++ b/compiler/dex/mir_optimization.cc
@@ -42,6 +42,11 @@ void MIRGraph::DoConstantPropagation(BasicBlock* bb) {
   MIR* mir;
 
   for (mir = bb->first_mir_insn; mir != NULL; mir = mir->next) {
+    // Skip pass if BB has MIR without SSA representation.
+    if (mir->ssa_rep == NULL) {
+       return;
+    }
+
     uint64_t df_attributes = oat_data_flow_attributes_[mir->dalvikInsn.opcode];
 
     DecodedInstruction *d_insn = &mir->dalvikInsn;
diff --git a/test/083-compiler-regressions/expected.txt b/test/083-compiler-regressions/expected.txt
index db50300..7576b02 100644
--- a/test/083-compiler-regressions/expected.txt
+++ b/test/083-compiler-regressions/expected.txt
@@ -16,6 +16,7 @@ b13679511Test finishing
 largeFrame passes
 largeFrameFloat passes
 mulBy1Test passes
+constantPropagationTest passes
 getterSetterTest passes
 identityTest passes
 wideGetterSetterTest passes
diff --git a/test/083-compiler-regressions/src/Main.java b/test/083-compiler-regressions/src/Main.java
index d32c037..6a12ca9 100644
--- a/test/083-compiler-regressions/src/Main.java
+++ b/test/083-compiler-regressions/src/Main.java
@@ -38,6 +38,7 @@ public class Main {
         largeFrameTest();
         largeFrameTestFloat();
         mulBy1Test();
+        constantPropagationTest();
         getterSetterTest();
         identityTest();
         wideGetterSetterTest();
@@ -766,6 +767,32 @@ public class Main {
         }
     }
 
+    static void constantPropagationTest() {
+        int i = 1;
+        int t = 1;
+        float z = 1F;
+        long h = 1L;
+        int g[] = new int[1];
+        int w = 1;
+        long f = 0;
+
+        for (int a = 1; a < 100; a++) {
+            try {
+                i = (int)(z);
+                h >>= (0 % t);
+            }
+            finally {
+                w = (int)(2 * (f * 6));
+            }
+        }
+
+        if (w == 0 && h == 1 && g[0] == 0) {
+            System.out.println("constantPropagationTest passes");
+        } else {
+            System.out.println("constantPropagationTest fails");
+        }
+    }
+
     static void b2296099Test() throws Exception {
        int x = -1190771042;
        int dist = 360530809;