[gcc r16-1640] Fix shrink wrap separate ICE for mingw [PR120741]

[Lili Cui]

https://gcc.gnu.org/g:4b739c020a90dfe2569a292c44b2293a94d4bff5

commit r16-1640-g4b739c020a90dfe2569a292c44b2293a94d4bff5
Author: Lili Cui <lili.cui@intel.com>
Date:   Tue Jun 24 10:49:43 2025 +0800

    Fix shrink wrap separate ICE for mingw [PR120741]
    
    gcc/ChangeLog:
    
            PR target/120741
            * config/i386/i386.cc (ix86_expand_prologue):
            Remove 1 assertion.
    
    gcc/testsuite/ChangeLog:
    
            PR target/120741
            * gcc.target/i386/pr120741.c: New test.
            * gcc.target/i386/shrink-wrap-separate-mingw.c: Likewise.

Diff:
---
 gcc/config/i386/i386.cc                            |  2 --
 gcc/testsuite/gcc.target/i386/pr120741.c           | 22 ++++++++++++++++++++++
 .../gcc.target/i386/shrink-wrap-separate-mingw.c   | 22 ++++++++++++++++++++++
 3 files changed, 44 insertions(+), 2 deletions(-)

diff --git a/gcc/config/i386/i386.cc b/gcc/config/i386/i386.cc
index fc3105919f45..84081ab12670 100644
--- a/gcc/config/i386/i386.cc
+++ b/gcc/config/i386/i386.cc
@@ -9443,8 +9443,6 @@ ix86_expand_prologue (void)
     }
   else
     {
-      gcc_assert (!crtl->shrink_wrapped_separate);
-
       rtx eax = gen_rtx_REG (Pmode, AX_REG);
       rtx r10 = NULL;
       const bool sp_is_cfa_reg = (m->fs.cfa_reg == stack_pointer_rtx);
diff --git a/gcc/testsuite/gcc.target/i386/pr120741.c b/gcc/testsuite/gcc.target/i386/pr120741.c
new file mode 100644
index 000000000000..b59a58c48b89
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr120741.c
@@ -0,0 +1,22 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -mstack-arg-probe" } */
+
+short __mingw_swformat_format;
+__builtin_va_list __mingw_swformat_arg;
+int __mingw_swformat_fc;
+typedef struct {
+  void *fp;
+  int bch[1024];
+} _IFP;
+void __mingw_swformat(_IFP *s) {
+  if (s->fp)
+    while (__mingw_swformat_format)
+      if (__mingw_swformat_fc == 'A')
+	*__builtin_va_arg(__mingw_swformat_arg, double *) = 0;
+}
+void
+__mingw_vswscanf (void)
+{
+  _IFP ifp;
+  __mingw_swformat(&ifp);
+}
diff --git a/gcc/testsuite/gcc.target/i386/shrink-wrap-separate-mingw.c b/gcc/testsuite/gcc.target/i386/shrink-wrap-separate-mingw.c
new file mode 100644
index 000000000000..58635e49647a
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/shrink-wrap-separate-mingw.c
@@ -0,0 +1,22 @@
+/* { dg-do compile { target *-*-mingw* *-*-cygwin* } } */
+/* { dg-options "-std=gnu99 -O2" } */
+
+short __mingw_swformat_format;
+__builtin_va_list __mingw_swformat_arg;
+int __mingw_swformat_fc;
+typedef struct {
+  void *fp;
+  int bch[1024];
+} _IFP;
+void __mingw_swformat(_IFP *s) {
+  if (s->fp)
+    while (__mingw_swformat_format)
+      if (__mingw_swformat_fc == 'A')
+        *__builtin_va_arg(__mingw_swformat_arg, double *) = 0;
+}
+void
+__mingw_vswscanf (void)
+{
+  _IFP ifp;
+  __mingw_swformat(&ifp);
+}