i386: Rewrite pushfl<mode>2 and popfl<mode>1 as unspecs

Flags reg is valid only with CC mode.

gcc/ChangeLog:

	* config/i386/i386-expand.h (gen_pushfl): New prototype.
	(gen_popfl): Ditto.
	* config/i386/i386-expand.cc (ix86_expand_builtin)
	[case IX86_BUILTIN_READ_FLAGS]: Use gen_pushfl.
	[case IX86_BUILTIN_WRITE_FLAGS]: Use gen_popfl.
	* config/i386/i386.cc (gen_pushfl): New function.
	(gen_popfl): Ditto.
	* config/i386/i386.md (unspec): Add UNSPEC_PUSHFL and UNSPEC_POPFL.
	(@pushfl<mode>2): Rename from *pushfl<mode>2.
	Rewrite as unspec using UNSPEC_PUSHFL.
	(@popfl<mode>1): Rename from *popfl<mode>1.
	Rewrite as unspec using UNSPEC_POPFL.

4 files changed, 44 insertions, 7 deletions

diff --git a/gcc/config/i386/i386-expand.cc b/gcc/config/i386/i386-expand.cc
index b52ec51..a8d871d 100644
--- a/gcc/config/i386/i386-expand.cc
+++ b/gcc/config/i386/i386-expand.cc
@@ -14265,7 +14265,7 @@ rdseed_step:
       if (ignore)
 	return const0_rtx;
 
-      emit_insn (gen_push (gen_rtx_REG (word_mode, FLAGS_REG)));
+      emit_insn (gen_pushfl ());
 
       if (optimize
 	  || target == NULL_RTX
@@ -14284,7 +14284,7 @@ rdseed_step:
 	op0 = copy_to_mode_reg (word_mode, op0);
 
       emit_insn (gen_push (op0));
-      emit_insn (gen_pop (gen_rtx_REG (word_mode, FLAGS_REG)));
+      emit_insn (gen_popfl ());
       return 0;
 
     case IX86_BUILTIN_KTESTC8:
diff --git a/gcc/config/i386/i386-expand.h b/gcc/config/i386/i386-expand.h
index 8e65f7d..1ea789c 100644
--- a/gcc/config/i386/i386-expand.h
+++ b/gcc/config/i386/i386-expand.h
@@ -45,7 +45,9 @@ enum calling_abi ix86_function_abi (const_tree fndecl);
 bool ix86_function_ms_hook_prologue (const_tree fn);
 void warn_once_call_ms2sysv_xlogues (const char *feature);
 rtx gen_push (rtx arg);
+rtx gen_pushfl (void);
 rtx gen_pop (rtx arg);
+rtx gen_popfl (void);
 rtx ix86_expand_builtin (tree exp, rtx target, rtx subtarget,
 			 machine_mode mode, int ignore);
 bool ix86_vectorize_vec_perm_const (machine_mode vmode, machine_mode op_mode,
diff --git a/gcc/config/i386/i386.cc b/gcc/config/i386/i386.cc
index 176ca65..683ac64 100644
--- a/gcc/config/i386/i386.cc
+++ b/gcc/config/i386/i386.cc
@@ -6465,6 +6465,24 @@ gen_push (rtx arg)
 		      arg);
 }
 
+rtx
+gen_pushfl (void)
+{
+  struct machine_function *m = cfun->machine;
+  rtx flags, mem;
+
+  if (m->fs.cfa_reg == stack_pointer_rtx)
+    m->fs.cfa_offset += UNITS_PER_WORD;
+  m->fs.sp_offset += UNITS_PER_WORD;
+
+  flags = gen_rtx_REG (CCmode, FLAGS_REG);
+
+  mem = gen_rtx_MEM (word_mode,
+		     gen_rtx_PRE_DEC (Pmode, stack_pointer_rtx));
+
+  return gen_pushfl2 (word_mode, mem, flags);
+}
+
 /* Generate an "pop" pattern for input ARG.  */
 
 rtx
@@ -6479,6 +6497,19 @@ gen_pop (rtx arg)
 						     stack_pointer_rtx)));
 }
 
+rtx
+gen_popfl (void)
+{
+  rtx flags, mem;
+
+  flags = gen_rtx_REG (CCmode, FLAGS_REG);
+
+  mem = gen_rtx_MEM (word_mode,
+		     gen_rtx_POST_INC (Pmode, stack_pointer_rtx));
+
+  return gen_popfl1 (word_mode, flags, mem);
+}
+
 /* Generate a "push2" pattern for input ARG.  */
 rtx
 gen_push2 (rtx mem, rtx reg1, rtx reg2)
diff --git a/gcc/config/i386/i386.md b/gcc/config/i386/i386.md
index 47d21f1..29289f4 100644
--- a/gcc/config/i386/i386.md
+++ b/gcc/config/i386/i386.md
@@ -115,6 +115,8 @@
   UNSPEC_SBB
   UNSPEC_CC_NE
   UNSPEC_STC
+  UNSPEC_PUSHFL
+  UNSPEC_POPFL
 
   ;; For SSE/MMX support:
   UNSPEC_FIX_NOTRUNC
@@ -2205,17 +2207,19 @@
   [(set_attr "type" "pop")
    (set_attr "mode" "<MODE>")])
 
-(define_insn "*pushfl<mode>2"
+(define_insn "@pushfl<mode>2"
   [(set (match_operand:W 0 "push_operand" "=<")
-	(match_operand:W 1 "flags_reg_operand"))]
+	(unspec:W [(match_operand:CC 1 "flags_reg_operand")]
+		  UNSPEC_PUSHFL))]
   ""
   "pushf{<imodesuffix>}"
   [(set_attr "type" "push")
    (set_attr "mode" "<MODE>")])
 
-(define_insn "*popfl<mode>1"
-  [(set (match_operand:W 0 "flags_reg_operand")
-	(match_operand:W 1 "pop_operand" ">"))]
+(define_insn "@popfl<mode>1"
+  [(set (match_operand:CC 0 "flags_reg_operand")
+	(unspec:CC [(match_operand:W 1 "pop_operand" ">")]
+		   UNSPEC_POPFL))]
   ""
   "popf{<imodesuffix>}"
   [(set_attr "type" "pop")