[PATCH v3] x86: Disable SSE on unwind-c.c and unwind-dw2.c

["H.J. Lu" <hjl.tools@gmail.com>]

Since eh_return doesn't work with stack realignment, disable SSE on
unwind-c.c and unwind-dw2.c to avoid stack realignment with the 4-byte
incoming stack to avoid SSE usage which is caused by

commit 609e8c492d62d92465460eae3d43dfc4b2c68288
Author: H.J. Lu <hjl.tools@gmail.com>
Date:   Sat Feb 26 14:17:23 2022 -0800

    x86: Always return pseudo register in ix86_gen_scratch_sse_rtx

when pseudo vector registers are used to expand memset.

gcc/

	PR target/104781
	* config/i386/i386.cc (ix86_expand_epilogue): Sorry if there is
	stack realignment with eh_return or regparm nested function.

gcc/testsuite/

	PR target/104781
	* gcc.target/i386/eh_return-1.c: Add -mincoming-stack-boundary=4.
	* gcc.target/i386/eh_return-2.c: Likewise.

libgcc/

	PR target/104781
	* config.host (tmake_file): Add i386/32/t-eh-return-no-sse for
	32-bit x86 Cygwin, MinGW and Solaris.
	* config/i386/32/t-eh-return-no-sse: New file.
---
 gcc/config/i386/i386.cc                     | 11 +++++++----
 gcc/testsuite/gcc.target/i386/eh_return-1.c |  2 +-
 gcc/testsuite/gcc.target/i386/eh_return-2.c |  2 +-
 libgcc/config.host                          | 13 +++++++++++++
 libgcc/config/i386/32/t-eh-return-no-sse    |  5 +++++
 5 files changed, 27 insertions(+), 6 deletions(-)
 create mode 100644 libgcc/config/i386/32/t-eh-return-no-sse

diff --git a/gcc/config/i386/i386.cc b/gcc/config/i386/i386.cc
index efa947f9795..4121f986221 100644
--- a/gcc/config/i386/i386.cc
+++ b/gcc/config/i386/i386.cc
@@ -9444,12 +9444,15 @@ ix86_expand_epilogue (int style)
 	  rtx sa = EH_RETURN_STACKADJ_RTX;
 	  rtx_insn *insn;
 
-	  /* %ecx can't be used for both DRAP register and eh_return.  */
-	  if (crtl->drap_reg)
-	    gcc_assert (REGNO (crtl->drap_reg) != CX_REG);
+	  /* Stack realignment doesn't work with eh_return.  */
+	  if (crtl->stack_realign_needed)
+	    sorry ("Stack realignment not supported with "
+		   "%<__builtin_eh_return%>");
 
 	  /* regparm nested functions don't work with eh_return.  */
-	  gcc_assert (!ix86_static_chain_on_stack);
+	  if (ix86_static_chain_on_stack)
+	    sorry ("regparm nested function not supported with "
+		   "%<__builtin_eh_return%>");
 
 	  if (frame_pointer_needed)
 	    {
diff --git a/gcc/testsuite/gcc.target/i386/eh_return-1.c b/gcc/testsuite/gcc.target/i386/eh_return-1.c
index b21fd75fc93..43f94f01a97 100644
--- a/gcc/testsuite/gcc.target/i386/eh_return-1.c
+++ b/gcc/testsuite/gcc.target/i386/eh_return-1.c
@@ -1,5 +1,5 @@
 /* { dg-do compile } */
-/* { dg-options "-O2 -march=haswell -mno-avx512f -mtune-ctrl=avx256_move_by_pieces" } */
+/* { dg-options "-O2 -mincoming-stack-boundary=4 -march=haswell -mno-avx512f -mtune-ctrl=avx256_move_by_pieces" } */
 
 struct _Unwind_Context
 {
diff --git a/gcc/testsuite/gcc.target/i386/eh_return-2.c b/gcc/testsuite/gcc.target/i386/eh_return-2.c
index f23f4492dac..cb762f92cc2 100644
--- a/gcc/testsuite/gcc.target/i386/eh_return-2.c
+++ b/gcc/testsuite/gcc.target/i386/eh_return-2.c
@@ -1,6 +1,6 @@
 /* PR target/101772  */
 /* { dg-do compile } */
-/* { dg-additional-options "-O0 -march=x86-64 -mstackrealign" } */
+/* { dg-additional-options "-O0 -mincoming-stack-boundary=4 -march=x86-64 -mstackrealign" } */
 
 struct _Unwind_Context _Unwind_Resume_or_Rethrow_this_context;
 
diff --git a/libgcc/config.host b/libgcc/config.host
index 094fd3ad254..1588ab6cf20 100644
--- a/libgcc/config.host
+++ b/libgcc/config.host
@@ -1583,3 +1583,16 @@ case ${host} in
   tmake_file="$tmake_file t-gthr-noweak"
   ;;
 esac
+
+case ${host} in
+i[34567]86-*-* | x86_64-*-*)
+  if test "${host_address}" = 32; then
+    case ${host} in
+    *-*-cygwin* | *-*-mingw* | *-*-solaris2*)
+      # Disable SSE on unwind-c.c and unwind-dw2.c to avoid stack
+      # realignment with the 4-byte aligned incoming stack.
+      tmake_file="${tmake_file} i386/${host_address}/t-eh-return-no-sse"
+      ;;
+    esac
+  fi
+esac
diff --git a/libgcc/config/i386/32/t-eh-return-no-sse b/libgcc/config/i386/32/t-eh-return-no-sse
new file mode 100644
index 00000000000..5a8c3135911
--- /dev/null
+++ b/libgcc/config/i386/32/t-eh-return-no-sse
@@ -0,0 +1,5 @@
+# Since eh_return doesn't work with stack realignment, disable SSE on
+# unwind-c.c and unwind-dw2.c to avoid stack realignment with the 4-byte
+# incoming stack.
+
+unwind-c.o unwind-c_s.o unwind-dw2.o unwind-dw2_s.o : HOST_LIBGCC2_CFLAGS += -mno-sse
-- 
2.35.1