re PR rtl-optimization/87466 (IRA and LRA spill all pseudos that are live across setjmp calls)

gcc/
	PR rtl-optimization/87466
	* target.def (setjmp_preserves_nonvolatile_regs_p): New target hook.
	* doc/tm.texi.in (TARGET_SETJMP_PRESERVES_NONVOLATILE_REGS_P): New hook.
	* doc/tm.texi: Regenerate.
	* ira-lives.c (process_bb_node_lives): Use the new target hook.
	* lra-lives.c (process_bb_lives): Likewise.
	* config/rs6000/rs6000.c (TARGET_SETJMP_PRESERVES_NONVOLATILE_REGS_P):
	Define.

gcc/testsuite/
	PR rtl-optimization/87466
	* gcc.target/powerpc/pr87466.c: New test.

From-SVN: r264842

gcc/config/rs6000/rs6000.c

@@ -1978,6 +1978,9 @@ static const struct attribute_spec rs6000_attribute_table[] =
 #undef TARGET_ASM_GLOBALIZE_DECL_NAME
 #define TARGET_ASM_GLOBALIZE_DECL_NAME rs6000_globalize_decl_name
 #endif
+
+#undef TARGET_SETJMP_PRESERVES_NONVOLATILE_REGS_P
+#define TARGET_SETJMP_PRESERVES_NONVOLATILE_REGS_P hook_bool_void_true
 
 
 /* Processor table.  */

gcc/doc/tm.texi

@@ -11008,6 +11008,19 @@ In order to enforce the representation of @code{mode},
 @code{mode}.
 @end deftypefn
 
+@deftypefn {Target Hook} bool TARGET_SETJMP_PRESERVES_NONVOLATILE_REGS_P (void)
+On some targets, it is assumed that the compiler will spill all pseudos
+  that are live across a call to @code{setjmp}, while other targets treat
+  @code{setjmp} calls as normal function calls.
+  
+  This hook returns false if @code{setjmp} calls do not preserve all
+  non-volatile registers so that gcc that must spill all pseudos that are
+  live across @code{setjmp} calls.  Define this to return true if the
+  target does not need to spill all pseudos live across @code{setjmp} calls.
+  The default implementation conservatively assumes all pseudos must be
+  spilled across @code{setjmp} calls.
+@end deftypefn
+
 @defmac STORE_FLAG_VALUE
 A C expression describing the value returned by a comparison operator
 with an integral mode and stored by a store-flag instruction

gcc/doc/tm.texi.in

@@ -7509,6 +7509,8 @@ You need not define this macro if it would always have the value of zero.
 
 @hook TARGET_MODE_REP_EXTENDED
 
+@hook TARGET_SETJMP_PRESERVES_NONVOLATILE_REGS_P
+
 @defmac STORE_FLAG_VALUE
 A C expression describing the value returned by a comparison operator
 with an integral mode and stored by a store-flag instruction

gcc/ira-lives.c

@@ -1207,8 +1207,9 @@ process_bb_node_lives (ira_loop_tree_node_t loop_tree_node)
 		     call, if this function receives a nonlocal
 		     goto.  */
 		  if (cfun->has_nonlocal_label
-		      || find_reg_note (insn, REG_SETJMP,
-					NULL_RTX) != NULL_RTX)
+		      || (!targetm.setjmp_preserves_nonvolatile_regs_p ()
+			  && (find_reg_note (insn, REG_SETJMP, NULL_RTX)
+			      != NULL_RTX)))
 		    {
 		      SET_HARD_REG_SET (OBJECT_CONFLICT_HARD_REGS (obj));
 		      SET_HARD_REG_SET (OBJECT_TOTAL_CONFLICT_HARD_REGS (obj));

gcc/lra-lives.c

@@ -895,8 +895,9 @@ process_bb_lives (basic_block bb, int &curr_point, bool dead_insn_p)
 	  sparseset_ior (pseudos_live_through_calls,
 			 pseudos_live_through_calls, pseudos_live);
 	  if (cfun->has_nonlocal_label
-	      || find_reg_note (curr_insn, REG_SETJMP,
-				NULL_RTX) != NULL_RTX)
+	      || (!targetm.setjmp_preserves_nonvolatile_regs_p ()
+		  && (find_reg_note (curr_insn, REG_SETJMP, NULL_RTX)
+		      != NULL_RTX)))
 	    sparseset_ior (pseudos_live_through_setjumps,
 			   pseudos_live_through_setjumps, pseudos_live);
 	}

gcc/target.def

@@ -3123,6 +3123,21 @@ In order to enforce the representation of @code{mode},\n\
  int, (scalar_int_mode mode, scalar_int_mode rep_mode),
  default_mode_rep_extended)
 
+ DEFHOOK
+(setjmp_preserves_nonvolatile_regs_p,
+ "On some targets, it is assumed that the compiler will spill all pseudos\n\
+  that are live across a call to @code{setjmp}, while other targets treat\n\
+  @code{setjmp} calls as normal function calls.\n\
+  \n\
+  This hook returns false if @code{setjmp} calls do not preserve all\n\
+  non-volatile registers so that gcc that must spill all pseudos that are\n\
+  live across @code{setjmp} calls.  Define this to return true if the\n\
+  target does not need to spill all pseudos live across @code{setjmp} calls.\n\
+  The default implementation conservatively assumes all pseudos must be\n\
+  spilled across @code{setjmp} calls.",
+ bool, (void),
+ hook_bool_void_false)
+
 /* True if MODE is valid for a pointer in __attribute__((mode("MODE"))).  */
 DEFHOOK
 (valid_pointer_mode,

gcc/testsuite/gcc.target/powerpc/pr87466.c

@@ -0,0 +1,19 @@
+/* { dg-do compile { target powerpc*-*-* } } */
+/* { dg-options "-O2" } */
+
+#include <stdlib.h>
+#include <setjmp.h>
+
+extern void foo (jmp_buf);
+
+long
+c (long var)
+{
+  jmp_buf env;
+  if (setjmp(env) != 0)
+    abort();
+  foo (env);
+  return var;
+}
+
+/* { dg-final { scan-assembler {\mmr\M} } } */