[gcc r14-4034] Fix PR111407--SSA corruption due to widening_mul opt on conflict across an abnormal edge

[gcc r14-4034] Fix PR111407--SSA corruption due to widening_mul opt on conflict across an abnormal edge

[Qing Zhao]

https://gcc.gnu.org/g:4aca1cfd6235090e48a53dab734437740671bbf3

commit r14-4034-g4aca1cfd6235090e48a53dab734437740671bbf3
Author: Qing Zhao <qing.zhao@oracle.com>
Date:   Fri Sep 15 13:46:52 2023 +0000

    Fix PR111407--SSA corruption due to widening_mul opt on conflict across an abnormal edge
    
    This is a bug in tree-ssa-math-opts.cc, 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.cc (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.

Diff:
---
 gcc/testsuite/gcc.dg/pr111407.c | 21 +++++++++++++++++++++
 gcc/tree-ssa-math-opts.cc       |  8 ++++++++
 2 files changed, 29 insertions(+)

diff --git a/gcc/testsuite/gcc.dg/pr111407.c b/gcc/testsuite/gcc.dg/pr111407.c
new file mode 100644
index 00000000000..a171074753f
--- /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.cc b/gcc/tree-ssa-math-opts.cc
index 3db69ad5733..51c14d6bad9 100644
--- a/gcc/tree-ssa-math-opts.cc
+++ b/gcc/tree-ssa-math-opts.cc
@@ -2755,6 +2755,14 @@ 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)