[gcc r12-8102] i386: Fix ICE caused by ix86_emit_i387_log1p [PR105214]

[Jakub Jelinek <jakub@gcc.gnu.org>]

https://gcc.gnu.org/g:d481d13786cb84f6294833538133dbd6f39d2e55

commit r12-8102-gd481d13786cb84f6294833538133dbd6f39d2e55
Author: Jakub Jelinek <jakub@redhat.com>
Date:   Tue Apr 12 09:19:11 2022 +0200

    i386: Fix ICE caused by ix86_emit_i387_log1p [PR105214]
    
    The following testcase ICEs, because ix86_emit_i387_log1p attempts to
    emit something like
      if (cond)
        some_code1;
      else
        some_code2;
    and emits a conditional jump using emit_jump_insn (standard way in
    the file) and an unconditional jump using emit_jump.
    The problem with that is that if there is pending stack adjustment,
    it isn't emitted before the conditional jump, but is before the
    unconditional jump and therefore stack is adjusted only conditionally
    (at the end of some_code1 above), which makes dwarf2 pass unhappy about it
    but is a serious wrong-code even if it doesn't ICE.
    
    This can be fixed either by emitting pending stack adjust before the
    conditional jump as the following patch does, or by not using
      emit_jump (label2);
    and instead hand inlining what that function does except for the
    pending stack adjustment, like:
      emit_jump_insn (targetm.gen_jump (label2));
      emit_barrier ();
    In that case there will be no stack adjustment in the sequence and
    it will be done later on somewhere else.
    
    2022-04-12  Jakub Jelinek  <jakub@redhat.com>
    
            PR target/105214
            * config/i386/i386-expand.cc (ix86_emit_i387_log1p): Call
            do_pending_stack_adjust.
    
            * gcc.dg/asan/pr105214.c: New test.

Diff:
---
 gcc/config/i386/i386-expand.cc       |  5 +++++
 gcc/testsuite/gcc.dg/asan/pr105214.c | 16 ++++++++++++++++
 2 files changed, 21 insertions(+)

diff --git a/gcc/config/i386/i386-expand.cc b/gcc/config/i386/i386-expand.cc
index 794315ee2f7..f6f2c1ea4e3 100644
--- a/gcc/config/i386/i386-expand.cc
+++ b/gcc/config/i386/i386-expand.cc
@@ -17291,6 +17291,11 @@ void ix86_emit_i387_log1p (rtx op0, rtx op1)
   rtx cst, cstln2, cst1;
   rtx_insn *insn;
 
+  /* The emit_jump call emits pending stack adjust, make sure it is emitted
+     before the conditional jump, otherwise the stack adjustment will be
+     only conditional.  */
+  do_pending_stack_adjust ();
+
   cst = const_double_from_real_value
     (REAL_VALUE_ATOF ("0.29289321881345247561810596348408353", XFmode), XFmode);
   cstln2 = force_reg (XFmode, standard_80387_constant_rtx (4)); /* fldln2 */
diff --git a/gcc/testsuite/gcc.dg/asan/pr105214.c b/gcc/testsuite/gcc.dg/asan/pr105214.c
new file mode 100644
index 00000000000..a755336c7d8
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/asan/pr105214.c
@@ -0,0 +1,16 @@
+/* PR target/105214 */
+/* { dg-do compile } */
+/* { dg-skip-if "" { *-*-* } { "*" } { "-O2" } } */
+/* { dg-options "-Ofast -fnon-call-exceptions -fexceptions -fstack-check=generic -fsanitize=address -fno-finite-math-only -fsignaling-nans -fno-associative-math" } */
+
+float f;
+void bar (int *);
+
+void
+foo (void)
+{
+  int a[1600], b[1];
+  f += __builtin_log1pf (f);
+  bar (a);
+  bar (b);
+}