[PR103024,PR103530] support throwing compares and non-boolean types

This patch adjusts the harden-compares pass to cope with compares that
end basic blocks, and to accept non-boolean integral types whose
conversion to boolean may have been discarded.

for  gcc/ChangeLog

	PR tree-optimization/103024
	PR middle-end/103530
	* gimple-harden-conditionals.cc (non_eh_succ_edge): New.
	(pass_harden_compares::execute): Accept 1-bit integral types,
	and cope with throwing compares.

for  gcc/testsuite/ChangeLog

	PR tree-optimization/103024
	PR middle-end/103530
	* g++.dg/pr103024.C: New.
	* g++.dg/pr103530.C: New.

diff --git a/gcc/gimple-harden-conditionals.cc b/gcc/gimple-harden-conditionals.cc
index 81867d6..5e709c6 100644 (file)
--- a/gcc/gimple-harden-conditionals.cc
+++ b/gcc/gimple-harden-conditionals.cc
@@ -35,6 +35,7 @@ along with GCC; see the file COPYING3.  If not see
 #include "basic-block.h"
 #include "cfghooks.h"
 #include "cfgloop.h"
+#include "tree-eh.h"
 #include "diagnostic.h"
 #include "intl.h"
 
@@ -359,6 +360,24 @@ make_pass_harden_conditional_branches (gcc::context *ctxt)
   return new pass_harden_conditional_branches (ctxt);
 }
 
+/* Return the fallthru edge of a block whose other edge is an EH
+   edge.  */
+static inline edge
+non_eh_succ_edge (basic_block bb)
+{
+  gcc_checking_assert (EDGE_COUNT (bb->succs) == 2);
+
+  edge ret = find_fallthru_edge (bb->succs);
+
+  int eh_idx = EDGE_SUCC (bb, 0) == ret;
+  edge eh = EDGE_SUCC (bb, eh_idx);
+
+  gcc_checking_assert (!(ret->flags & EDGE_EH)
+                      && (eh->flags & EDGE_EH));
+
+  return ret;
+}
+
 /* Harden boolean-yielding compares in FUN.  */
 
 unsigned int
@@ -449,7 +468,11 @@ pass_harden_compares::execute (function *fun)
        if (VECTOR_TYPE_P (TREE_TYPE (op1)))
          continue;
 
-       gcc_checking_assert (TREE_CODE (TREE_TYPE (lhs)) == BOOLEAN_TYPE);
+       /* useless_type_conversion_p enables conversions from 1-bit
+          integer types to boolean to be discarded.  */
+       gcc_checking_assert (TREE_CODE (TREE_TYPE (lhs)) == BOOLEAN_TYPE
+                            || (INTEGRAL_TYPE_P (TREE_TYPE (lhs))
+                                && TYPE_PRECISION (TREE_TYPE (lhs)) == 1));
 
        tree rhs = copy_ssa_name (lhs);
 
@@ -460,6 +483,20 @@ pass_harden_compares::execute (function *fun)
           won't be debug stmts only.  */
        gsi_next_nondebug (&gsi_split);
 
+       bool throwing_compare_p = stmt_ends_bb_p (asgn);
+       if (throwing_compare_p)
+         {
+           basic_block nbb = split_edge (non_eh_succ_edge
+                                         (gimple_bb (asgn)));
+           gsi_split = gsi_start_bb (nbb);
+
+           if (dump_file)
+             fprintf (dump_file,
+                      "Splitting non-EH edge from block %i into %i"
+                      " after a throwing compare\n",
+                      gimple_bb (asgn)->index, nbb->index);
+         }
+
        bool same_p = (op1 == op2);
        op1 = detach_value (loc, &gsi_split, op1);
        op2 = same_p ? op1 : detach_value (loc, &gsi_split, op2);
@@ -473,17 +510,46 @@ pass_harden_compares::execute (function *fun)
        if (!gsi_end_p (gsi_split))
          {
            gsi_prev (&gsi_split);
-           split_block (bb, gsi_stmt (gsi_split));
+           basic_block obb = gsi_bb (gsi_split);
+           basic_block nbb = split_block (obb, gsi_stmt (gsi_split))->dest;
            gsi_next (&gsi_split);
            gcc_checking_assert (gsi_end_p (gsi_split));
 
            single_succ_edge (bb)->goto_locus = loc;
 
            if (dump_file)
-             fprintf (dump_file, "Splitting block %i\n", bb->index);
+             fprintf (dump_file,
+                      "Splitting block %i into %i"
+                      " before the conditional trap branch\n",
+                      obb->index, nbb->index);
+         }
+
+       /* If the check assignment must end a basic block, we can't
+          insert the conditional branch in the same block, so split
+          the block again, and prepare to insert the conditional
+          branch in the new block.
+
+          Also assign an EH region to the compare.  Even though it's
+          unlikely that the hardening compare will throw after the
+          original compare didn't, the compiler won't even know that
+          it's the same compare operands, so add the EH edge anyway.  */
+       if (throwing_compare_p)
+         {
+           add_stmt_to_eh_lp (asgnck, lookup_stmt_eh_lp (asgn));
+           make_eh_edges (asgnck);
+
+           basic_block nbb = split_edge (non_eh_succ_edge
+                                         (gimple_bb (asgnck)));
+           gsi_split = gsi_start_bb (nbb);
+
+           if (dump_file)
+             fprintf (dump_file,
+                      "Splitting non-EH edge from block %i into %i after"
+                      " the newly-inserted reversed throwing compare\n",
+                      gimple_bb (asgnck)->index, nbb->index);
          }
 
-       gcc_checking_assert (single_succ_p (bb));
+       gcc_checking_assert (single_succ_p (gsi_bb (gsi_split)));
 
        insert_check_and_trap (loc, &gsi_split, EDGE_TRUE_VALUE,
                               EQ_EXPR, lhs, rhs);

diff --git a/gcc/testsuite/g++.dg/pr103024.C b/gcc/testsuite/g++.dg/pr103024.C
new file mode 100644 (file)
index 0000000..15e68d4
--- /dev/null
+++ b/gcc/testsuite/g++.dg/pr103024.C
@@ -0,0 +1,12 @@
+/* { dg-do compile } */
+/* { dg-options "-fnon-call-exceptions -fharden-compares -fsignaling-nans" } */
+
+struct G4ErrorMatrix {
+  G4ErrorMatrix(int);
+  ~G4ErrorMatrix();
+};
+double PropagateError_charge;
+void PropagateError() {
+  G4ErrorMatrix transf(0);
+  int field(PropagateError_charge && field);
+}

diff --git a/gcc/testsuite/g++.dg/pr103530.C b/gcc/testsuite/g++.dg/pr103530.C
new file mode 100644 (file)
index 0000000..c1d2059
--- /dev/null
+++ b/gcc/testsuite/g++.dg/pr103530.C
@@ -0,0 +1,27 @@
+/* { dg-do compile } */
+/* { dg-options "-O -fharden-compares -Wno-c++11-extensions" } */
+
+enum E:bool
+{ E0, E1 };
+
+int x;
+
+E
+baz (E rtt)
+{
+  return rtt == E0 ? E1 : E0;
+}
+
+bool bar ();
+
+void
+foo (E)
+{
+  E a = x ? E1 : E0;
+  if (bar ())
+    if (bar ())
+      {
+       E b = baz (a);
+       foo (b);
+      }
+}