[gcc(refs/users/guojiufu/heads/guojiufu-branch)] testcase for last_vuse in FRE

[Jiu Fu Guo]

https://gcc.gnu.org/g:81ef67c10a3db7d789c7be653dba0a6e6a3e9958

commit 81ef67c10a3db7d789c7be653dba0a6e6a3e9958
Author: Richard Biener <rguenther@suse.de>
Date:   Tue Feb 25 12:19:33 2020 +0100

    testcase for last_vuse in FRE
    
    This adds a testcase for some basic FRE functionality.
    
    2020-02-25  Richard Biener  <rguenther@suse.de>
    
            * gcc.dg/tree-ssa/ssa-fre-86.c: New testcase.

Diff:
---
 gcc/testsuite/ChangeLog                    |  4 ++++
 gcc/testsuite/gcc.dg/tree-ssa/ssa-fre-86.c | 20 ++++++++++++++++++++
 2 files changed, 24 insertions(+)

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index d25296df65b..10bbb73fc3d 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,7 @@
+2020-02-25  Richard Biener  <rguenther@suse.de>
+
+	* gcc.dg/tree-ssa/ssa-fre-86.c: New testcase.
+
 2020-02-25  Richard Biener  <rguenther@suse.de>
 
 	PR tree-optimization/93868
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/ssa-fre-86.c b/gcc/testsuite/gcc.dg/tree-ssa/ssa-fre-86.c
new file mode 100644
index 00000000000..d3da22c46c1
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/ssa-fre-86.c
@@ -0,0 +1,20 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-tree-fre1" } */
+
+int foo(int *p, int b, float *q)
+{
+  int tem;
+  if (b)
+    {
+      *q = 0;
+      tem = *p;
+    }
+  else
+    {
+      *q = 1;
+      tem = *p;
+    }
+  return *p - tem;
+}
+
+/* { dg-final { scan-tree-dump "return 0;" "fre1" } } */