[PATCH][Backport][GCC10] Fix SSA corruption due to widening_mul opt on conflict across an abnormal edge [PR111407]

[Qing Zhao <qing.zhao@oracle.com>]

This is a bug in tree-ssa-math-opts.c, when applying the widening mul
optimization, the compiler needs to check whether the operand is in a
ABNORMAL PHI, if YES, we should avoid the transformation.

	PR tree-optimization/111407

gcc/ChangeLog:

	* tree-ssa-math-opts.c (convert_mult_to_widen): Avoid the transform
	when one of the operands is subject to abnormal coalescing.

gcc/testsuite/ChangeLog:

	* gcc.dg/pr111407.c: New test.

(cherry picked from commit 4aca1cfd6235090e48a53dab734437740671bbf3)

bootstraped and regression tested on both aarch64 and x86.

Okay for commit to GCC10?

thanks.

Qing
---
 gcc/testsuite/gcc.dg/pr111407.c | 21 +++++++++++++++++++++
 gcc/tree-ssa-math-opts.c        |  8 ++++++++
 2 files changed, 29 insertions(+)
 create mode 100644 gcc/testsuite/gcc.dg/pr111407.c

diff --git a/gcc/testsuite/gcc.dg/pr111407.c b/gcc/testsuite/gcc.dg/pr111407.c
new file mode 100644
index 000000000000..a171074753f9
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr111407.c
@@ -0,0 +1,21 @@
+/* PR tree-optimization/111407*/
+/* { dg-do compile } */
+/* { dg-options "-O2" } */
+enum { SEND_TOFILE } __sigsetjmp();
+void fclose();
+void foldergets();
+void sendpart_stats(int *p1, int a1, int b1) {
+ int *a = p1;
+ fclose();
+ p1 = 0;
+ long t = b1;
+ if (__sigsetjmp()) {
+   {
+     long t1 = a1;
+     a1+=1;
+     fclose(a1*(long)t1);
+   }
+ }
+ if (p1)
+   fclose();
+}
diff --git a/gcc/tree-ssa-math-opts.c b/gcc/tree-ssa-math-opts.c
index dd0b8c6f0577..47981da20e05 100644
--- a/gcc/tree-ssa-math-opts.c
+++ b/gcc/tree-ssa-math-opts.c
@@ -2543,6 +2543,14 @@ convert_mult_to_widen (gimple *stmt, gimple_stmt_iterator *gsi)
   if (!is_widening_mult_p (stmt, &type1, &rhs1, &type2, &rhs2))
     return false;
 
+  /* if any one of rhs1 and rhs2 is subject to abnormal coalescing,
+     avoid the tranform. */
+  if ((TREE_CODE (rhs1) == SSA_NAME
+       && SSA_NAME_OCCURS_IN_ABNORMAL_PHI (rhs1))
+      || (TREE_CODE (rhs2) == SSA_NAME
+	  && SSA_NAME_OCCURS_IN_ABNORMAL_PHI (rhs2)))
+    return false;
+
   to_mode = SCALAR_INT_TYPE_MODE (type);
   from_mode = SCALAR_INT_TYPE_MODE (type1);
   if (to_mode == from_mode)
-- 
2.31.1