[gcc r13-2653] PR target/106877: Robustify reg-stack to malformed asm.

[Roger Sayle <sayle@gcc.gnu.org>]

https://gcc.gnu.org/g:ff85f0afc7d5684378944f88a9bc9b931034788b

commit r13-2653-gff85f0afc7d5684378944f88a9bc9b931034788b
Author: Roger Sayle <roger@nextmovesoftware.com>
Date:   Tue Sep 13 19:49:20 2022 +0100

    PR target/106877: Robustify reg-stack to malformed asm.
    
    This patch resolves PR target/106877 an ICE-on-invalid inline-asm
    regression.  An innocent upstream change means that the test case
    from PR inline-asm/84683 now hits a different assert in reg-stack.cc's
    move_for_stack_reg.  Fixed by duplicating Jakub's solution to PR 84683
    https://gcc.gnu.org/pipermail/gcc-patches/2018-March/495193.html at
    this second (similar) gcc_assert.
    
    2022-09-13  Roger Sayle  <roger@nextmovesoftware.com>
    
    gcc/ChangeLog
            PR target/106877
            * reg-stack.cc (move_for_stack_reg): Check for any_malformed_asm
            in gcc_assert.
    
    gcc/testsuite/ChangeLog
            PR target/106877
            * g++.dg/ext/pr106877.C: New test case.

Diff:
---
 gcc/reg-stack.cc                    |  3 ++-
 gcc/testsuite/g++.dg/ext/pr106877.C | 13 +++++++++++++
 2 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/gcc/reg-stack.cc b/gcc/reg-stack.cc
index fd032501ad9..95e0e614e46 100644
--- a/gcc/reg-stack.cc
+++ b/gcc/reg-stack.cc
@@ -1073,7 +1073,8 @@ move_for_stack_reg (rtx_insn *insn, stack_ptr regstack, rtx pat)
 	      break;
 
 	  /* The destination must be dead, or life analysis is borked.  */
-	  gcc_assert (get_hard_regnum (regstack, dest) < FIRST_STACK_REG);
+	  gcc_assert (get_hard_regnum (regstack, dest) < FIRST_STACK_REG
+		      || any_malformed_asm);
 
 	  /* If the source is not live, this is yet another case of
 	     uninitialized variables.  Load up a NaN instead.  */
diff --git a/gcc/testsuite/g++.dg/ext/pr106877.C b/gcc/testsuite/g++.dg/ext/pr106877.C
new file mode 100644
index 00000000000..6bffed9beae
--- /dev/null
+++ b/gcc/testsuite/g++.dg/ext/pr106877.C
@@ -0,0 +1,13 @@
+// PR target/106877
+// { dg-do compile { target i?86-*-* x86_64-*-* } }
+// { dg-options "-O1 -m16 -mtune=sandybridge -flive-range-shrinkage -fno-dce" }
+
+void
+foo (float b, double c)
+{
+  for (int e = 0; e < 2; e++)
+    {
+      asm volatile ("" : "+f" (c));	// { dg-error "must specify a single register" }
+      asm ("" : "+rm" (c = b));
+    }
+}