[PATCH] sra: Disqualify bases of operands of asm gotos

[Martin Jambor]

Hi,

PR 110422 shows that SRA can ICE assuming there is a single edge
outgoing from a block terminated with an asm goto.  We need that for
BB-terminating statements so that any adjustments they make to the
aggregates can be copied over to their replacements.  Because we can't
have that after ASM gotos, we need to punt.

Bootstrapped and tested on x86_64-linux, OK for master?  It will need
some tweaking for release branches, is it in principle OK for them too
(after testing)?

Thanks,

Martin


gcc/ChangeLog:

2024-01-17  Martin Jambor  <mjam...@suse.cz>

        PR tree-optimization/110422
        * tree-sra.cc (scan_function): Disqualify bases of operands of asm
        gotos.

gcc/testsuite/ChangeLog:

2024-01-17  Martin Jambor  <mjam...@suse.cz>

        PR tree-optimization/110422
        * gcc.dg/torture/pr110422.c: New test.
---
 gcc/testsuite/gcc.dg/torture/pr110422.c | 10 +++++++++
 gcc/tree-sra.cc                         | 29 ++++++++++++++++++++-----
 2 files changed, 33 insertions(+), 6 deletions(-)
 create mode 100644 gcc/testsuite/gcc.dg/torture/pr110422.c

diff --git a/gcc/testsuite/gcc.dg/torture/pr110422.c 
b/gcc/testsuite/gcc.dg/torture/pr110422.c
new file mode 100644
index 00000000000..2e171a7a19e
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/torture/pr110422.c
@@ -0,0 +1,10 @@
+/* { dg-do compile } */
+
+struct T { int x; };
+int foo(void) {
+  struct T v;
+  asm goto("" : "+r"(v.x) : : : lab);
+  return 0;
+lab:
+  return -5;
+}
diff --git a/gcc/tree-sra.cc b/gcc/tree-sra.cc
index 6a1141b7377..f8e71ec48b9 100644
--- a/gcc/tree-sra.cc
+++ b/gcc/tree-sra.cc
@@ -1559,15 +1559,32 @@ scan_function (void)
            case GIMPLE_ASM:
              {
                gasm *asm_stmt = as_a <gasm *> (stmt);
-               for (i = 0; i < gimple_asm_ninputs (asm_stmt); i++)
+               if (stmt_ends_bb_p (asm_stmt)
+                   && !single_succ_p (gimple_bb (asm_stmt)))
                  {
-                   t = TREE_VALUE (gimple_asm_input_op (asm_stmt, i));
-                   ret |= build_access_from_expr (t, asm_stmt, false);
+                   for (i = 0; i < gimple_asm_ninputs (asm_stmt); i++)
+                     {
+                       t = TREE_VALUE (gimple_asm_input_op (asm_stmt, i));
+                       disqualify_base_of_expr (t, "OP of asm goto.");
+                     }
+                   for (i = 0; i < gimple_asm_noutputs (asm_stmt); i++)
+                     {
+                       t = TREE_VALUE (gimple_asm_output_op (asm_stmt, i));
+                       disqualify_base_of_expr (t, "OP of asm goto.");
+                     }
                  }
-               for (i = 0; i < gimple_asm_noutputs (asm_stmt); i++)
+               else
                  {
-                   t = TREE_VALUE (gimple_asm_output_op (asm_stmt, i));
-                   ret |= build_access_from_expr (t, asm_stmt, true);
+                   for (i = 0; i < gimple_asm_ninputs (asm_stmt); i++)
+                     {
+                       t = TREE_VALUE (gimple_asm_input_op (asm_stmt, i));
+                       ret |= build_access_from_expr (t, asm_stmt, false);
+                     }
+                   for (i = 0; i < gimple_asm_noutputs (asm_stmt); i++)
+                     {
+                       t = TREE_VALUE (gimple_asm_output_op (asm_stmt, i));
+                       ret |= build_access_from_expr (t, asm_stmt, true);
+                     }
                  }
              }
              break;
-- 
2.43.0