i386.c (ix86_function_regparm): Save an extra register for -fsplit-stack with DECL_ST...

	* config/i386/i386.c (ix86_function_regparm): Save an extra
	register for -fsplit-stack with DECL_STATIC_CHAIN.

From-SVN: r246286

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 7164d10..1385d92 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2017-03-20  Ian Lance Taylor  <iant@google.com>
+
+       * config/i386/i386.c (ix86_function_regparm): Save an extra
+       register for -fsplit-stack with DECL_STATIC_CHAIN.
+
 2017-03-17  Palmer Dabbelt  <palmer@dabbelt.com>
 
        PR target/79912

diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
index f58d529..259f97b 100644 (file)
--- a/gcc/config/i386/i386.c
+++ b/gcc/config/i386/i386.c
@@ -7975,8 +7975,14 @@ ix86_function_regparm (const_tree type, const_tree decl)
                local_regparm = 2;
 
              /* Save a register for the split stack.  */
-             if (local_regparm == 3 && flag_split_stack)
-               local_regparm = 2;
+             if (flag_split_stack)
+               {
+                 if (local_regparm == 3)
+                   local_regparm = 2;
+                 else if (local_regparm == 2
+                          && DECL_STATIC_CHAIN (target->decl))
+                   local_regparm = 1;
+               }
 
              /* Each fixed register usage increases register pressure,
                 so less registers should be used for argument passing.