forwprop: Fix looping after fold_stmt and some forwprop local folds happen

r10-2587-gcc19f80ceb27cc added a loop over the current statment if there was
a change. Except in some cases it turns out changed will turn from true to false
because instead of doing |= after the fold_stmt, there was an just an `=`.
This fixes that and now we loop even if fold_stmt changed the statement and
there was a local fold that happened.

gcc/ChangeLog:

	* tree-ssa-forwprop.cc (pass_forwprop::execute): Use `|=` for
	changed on the local folding.

Signed-off-by: Andrew Pinski <quic_apinski@quicinc.com>

diff --git a/gcc/tree-ssa-forwprop.cc b/gcc/tree-ssa-forwprop.cc
index fafc4d6b77ab9bc0ce2a53a7623c3dac8ae0a4b1..bcdec1aadc3eb19875f129cc1879e9cf67b0a748 100644 (file)
--- a/gcc/tree-ssa-forwprop.cc
+++ b/gcc/tree-ssa-forwprop.cc
@@ -4564,7 +4564,7 @@ pass_forwprop::execute (function *fun)
                          bitmap_set_bit (to_purge, bb->index);
                        if (did_something == 2)
                          cfg_changed = true;
-                       changed = did_something != 0;
+                       changed |= did_something != 0;
                      }
                    else if ((code == PLUS_EXPR
                              || code == BIT_IOR_EXPR
@@ -4580,15 +4580,15 @@ pass_forwprop::execute (function *fun)
                      }
                    else if (code == CONSTRUCTOR
                             && TREE_CODE (TREE_TYPE (rhs1)) == VECTOR_TYPE)
-                     changed = simplify_vector_constructor (&gsi);
+                     changed |= simplify_vector_constructor (&gsi);
                    else if (code == ARRAY_REF)
-                     changed = simplify_count_trailing_zeroes (&gsi);
+                     changed |= simplify_count_trailing_zeroes (&gsi);
                    break;
                  }
 
                case GIMPLE_SWITCH:
-                 changed = simplify_gimple_switch (as_a <gswitch *> (stmt),
-                                                   edges_to_remove);
+                 changed |= simplify_gimple_switch (as_a <gswitch *> (stmt),
+                                                    edges_to_remove);
                  break;
 
                case GIMPLE_COND:
@@ -4597,7 +4597,7 @@ pass_forwprop::execute (function *fun)
                                                        (as_a <gcond *> (stmt));
                    if (did_something == 2)
                      cfg_changed = true;
-                   changed = did_something != 0;
+                   changed |= did_something != 0;
                    break;
                  }
 
@@ -4606,7 +4606,7 @@ pass_forwprop::execute (function *fun)
                    tree callee = gimple_call_fndecl (stmt);
                    if (callee != NULL_TREE
                        && fndecl_built_in_p (callee, BUILT_IN_NORMAL))
-                     changed = simplify_builtin_call (&gsi, callee);
+                     changed |= simplify_builtin_call (&gsi, callee);
                    break;
                  }