[PATCH] Allow fusion of stack_protect_test_<mode> with adjacent conditional jump (PR target/90568)

[Jakub Jelinek]

Hi!

On Thu, May 23, 2019 at 12:40:51AM +0200, Jakub Jelinek wrote:
> Incrementally, we should consider handling e.g. *subsi_2{,_zext} and similar
> patterns and also this stack_protect_test_[sd]i in ix86_macro_fusion_pair_p,
> not sure if unconditionally, or only when tuning for skylake+ / generic.

Actually, *subsi_2 etc. is already supported, the following patch adds macro
fusion support for the stack_protect_test_?i.
Additionally, it fixes a compile time inefficiency, while recog_memoized
and extract_constrain_insn_cached do caching, get_attr_type uses those two
plus often calls various predicates which are not cached, so calling
get_attr_type 4-7 times in a row on the same instruction isn't a very good
idea.

Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?

2019-05-23  Jakub Jelinek  <jakub@redhat.com>

	PR target/90568
	* config/i386/x86-tune-sched.c (ix86_macro_funsion_pair_p): Call
	gen_attr_type just once instead of 4-7 times.  Formatting fixes.
	Handle stack_protect_test_<mode> codegen similarly to corresponding
	sub instruction.

--- gcc/config/i386/x86-tune-sched.c.jj	2019-01-01 12:37:31.608737849 +0100
+++ gcc/config/i386/x86-tune-sched.c	2019-05-23 12:28:29.826740473 +0200
@@ -525,6 +525,7 @@ ix86_macro_fusion_pair_p (rtx_insn *cond
   enum rtx_code ccode;
   rtx compare_set = NULL_RTX, test_if, cond;
   rtx alu_set = NULL_RTX, addr = NULL_RTX;
+  enum attr_type condgen_type;
 
   if (!any_condjump_p (condjmp))
     return false;
@@ -538,15 +539,26 @@ ix86_macro_fusion_pair_p (rtx_insn *cond
       || !modified_in_p (cc_reg_1, condgen))
     return false;
 
-  if (get_attr_type (condgen) != TYPE_TEST
-      && get_attr_type (condgen) != TYPE_ICMP
-      && get_attr_type (condgen) != TYPE_INCDEC
-      && get_attr_type (condgen) != TYPE_ALU)
+  condgen_type = get_attr_type (condgen);
+  if (condgen_type == TYPE_MULTI
+      && (INSN_CODE (condgen) == CODE_FOR_stack_protect_test_di
+	  || INSN_CODE (condgen) == CODE_FOR_stack_protect_test_si)
+      && TARGET_FUSE_ALU_AND_BRANCH)
+    {
+      /* stack_protect_test_<mode> ends with a sub, which subtracts
+	 a non-rip special memory operand from a GPR.  */
+      src = NULL_RTX;
+      alu_set = XVECEXP (PATTERN (condgen), 0, 1);
+      goto handle_stack_protect_test;
+    }
+  else if (condgen_type != TYPE_TEST
+	   && condgen_type != TYPE_ICMP
+	   && condgen_type != TYPE_INCDEC
+	   && condgen_type != TYPE_ALU)
     return false;
 
   compare_set = single_set (condgen);
-  if (compare_set == NULL_RTX
-      && !TARGET_FUSE_ALU_AND_BRANCH)
+  if (compare_set == NULL_RTX && !TARGET_FUSE_ALU_AND_BRANCH)
     return false;
 
   if (compare_set == NULL_RTX)
@@ -571,10 +583,8 @@ ix86_macro_fusion_pair_p (rtx_insn *cond
 
   /* Macro-fusion for cmp/test MEM-IMM + conditional jmp is not
      supported.  */
-  if ((MEM_P (XEXP (src, 0))
-       && CONST_INT_P (XEXP (src, 1)))
-      || (MEM_P (XEXP (src, 1))
-	  && CONST_INT_P (XEXP (src, 0))))
+  if ((MEM_P (XEXP (src, 0)) && CONST_INT_P (XEXP (src, 1)))
+      || (MEM_P (XEXP (src, 1)) && CONST_INT_P (XEXP (src, 0))))
     return false;
 
   /* No fusion for RIP-relative address.  */
@@ -583,29 +593,27 @@ ix86_macro_fusion_pair_p (rtx_insn *cond
   else if (MEM_P (XEXP (src, 1)))
     addr = XEXP (XEXP (src, 1), 0);
 
-  if (addr) {
-    ix86_address parts;
-    int ok = ix86_decompose_address (addr, &parts);
-    gcc_assert (ok);
-
-    if (ix86_rip_relative_addr_p (&parts))
-      return false;
-  }
+  if (addr)
+    {
+      ix86_address parts;
+      int ok = ix86_decompose_address (addr, &parts);
+      gcc_assert (ok);
+
+      if (ix86_rip_relative_addr_p (&parts))
+	return false;
+    }
 
+ handle_stack_protect_test:
   test_if = SET_SRC (pc_set (condjmp));
   cond = XEXP (test_if, 0);
   ccode = GET_CODE (cond);
   /* Check whether conditional jump use Sign or Overflow Flags.  */
   if (!TARGET_FUSE_CMP_AND_BRANCH_SOFLAGS
-      && (ccode == GE
-          || ccode == GT
-	  || ccode == LE
-	  || ccode == LT))
+      && (ccode == GE || ccode == GT || ccode == LE || ccode == LT))
     return false;
 
   /* Return true for TYPE_TEST and TYPE_ICMP.  */
-  if (get_attr_type (condgen) == TYPE_TEST
-      || get_attr_type (condgen) == TYPE_ICMP)
+  if (condgen_type == TYPE_TEST || condgen_type == TYPE_ICMP)
     return true;
 
   /* The following is the case that macro-fusion for alu + jmp.  */
@@ -619,11 +627,8 @@ ix86_macro_fusion_pair_p (rtx_insn *cond
 
   /* Macro-fusion for inc/dec + unsigned conditional jump is not
      supported.  */
-  if (get_attr_type (condgen) == TYPE_INCDEC
-      && (ccode == GEU
-	  || ccode == GTU
-	  || ccode == LEU
-	  || ccode == LTU))
+  if (condgen_type == TYPE_INCDEC
+      && (ccode == GEU || ccode == GTU || ccode == LEU || ccode == LTU))
     return false;
 
   return true;


	Jakub