From 47af5d5065b69b1038cde6903ae47725f3b8894d Mon Sep 17 00:00:00 2001
From: James Van Artsdalen <jrv@gnu.org>
Date: Wed, 30 Dec 1992 03:37:29 +0000
Subject: [PATCH] (bit complement): Constrain inputs and outputs to match,

instead of using match_dup.
(zero_extract test): Reenable with separate patterns to match
QImode and SImode zero_extract.

From-SVN: r2984
---
 gcc/config/i386/i386.md | 81 +++++++++++++++++++++++++++--------------
 1 file changed, 53 insertions(+), 28 deletions(-)

diff --git a/gcc/config/i386/i386.md b/gcc/config/i386/i386.md
index dca7bb61464..ccd4583cb69 100644
--- a/gcc/config/i386/i386.md
+++ b/gcc/config/i386/i386.md
@@ -2928,10 +2928,10 @@
 ;; Bit complement.  See comments on previous pattern.
 ;; ??? Is this really worthwhile?
 (define_insn ""
-  [(set (match_operand:SI 0 "general_operand" "+rm")
+  [(set (match_operand:SI 0 "general_operand" "=rm")
 	(xor:SI (ashift:SI (const_int 1)
 			   (match_operand:SI 1 "general_operand" "r"))
-		(match_dup 0)))]
+		(match_operand:SI 2 "general_operand" "0")))]
   "! TARGET_486 && GET_CODE (operands[1]) != CONST_INT"
   "*
 {
@@ -2940,22 +2940,18 @@
   return AS2 (btc%L0,%1,%0);
 }")
 
-/* ??? This works, but that SUBREG looks dangerous.
 (define_insn ""
-  [(set (match_operand:HI 0 "general_operand" "+rm")
-	(xor:HI (subreg:HI
-		 (ashift:SI (const_int 1)
-			    (sign_extend:SI
-			     (match_operand:HI 1 "nonimmediate_operand" "r"))) 0)
-		(match_dup 0)))]
-  "! TARGET_486"
+  [(set (match_operand:SI 0 "general_operand" "=rm")
+	(xor:SI (match_operand:SI 1 "general_operand" "0")
+		(ashift:SI (const_int 1)
+			   (match_operand:SI 2 "general_operand" "r"))))]
+  "! TARGET_486 && GET_CODE (operands[2]) != CONST_INT"
   "*
 {
   CC_STATUS_INIT;
 
-  return AS2 (btc%W0,%1,%0);
+  return AS2 (btc%L0,%2,%0);
 }")
-*/
 
 ;; Recognizers for bit-test instructions.
 
@@ -2967,16 +2963,56 @@
 ;; don't allow a MEM in the operand predicate without allowing it in the
 ;; constraint.
 
+(define_insn ""
+  [(set (cc0) (zero_extract (match_operand:SI 0 "register_operand" "r")
+			    (const_int 1)
+			    (match_operand:SI 1 "general_operand" "r")))]
+  "GET_CODE (operands[1]) != CONST_INT"
+  "*
+{
+  cc_status.flags |= CC_Z_IN_NOT_C;
+  return AS2 (bt%L0,%1,%0);
+}")
+
+(define_insn ""
+  [(set (cc0) (zero_extract (match_operand:SI 0 "register_operand" "r")
+			    (match_operand:SI 1 "const_int_operand" "n")
+			    (match_operand:SI 2 "const_int_operand" "n")))]
+  ""
+  "*
+{
+  unsigned int mask;
+
+  mask = ((1 << INTVAL (operands[1])) - 1) << INTVAL (operands[2]);
+  operands[1] = GEN_INT (mask);
+
+  if (QI_REG_P (operands[0]))
+    {
+      if ((mask & ~0xff) == 0)
+        {
+	  cc_status.flags |= CC_NOT_NEGATIVE;
+	  return AS2 (test%B0,%1,%b0);
+	}
+
+      if ((mask & ~0xff00) == 0)
+        {
+	  cc_status.flags |= CC_NOT_NEGATIVE;
+	  operands[1] = GEN_INT (mask >> 8);
+	  return AS2 (test%B0,%1,%h0);
+	}
+    }
+
+  return AS2 (test%L0,%1,%0);
+}")
+
 ;; ??? All bets are off if operand 0 is a volatile MEM reference.
+;; The CPU may access unspecified bytes around the actual target byte.
 
-/*
 (define_insn ""
-  [(set (cc0) (zero_extract (match_operand 0 "general_operand" "rm")
+  [(set (cc0) (zero_extract (match_operand:QI 0 "general_operand" "rm")
 			    (match_operand:SI 1 "const_int_operand" "n")
 			    (match_operand:SI 2 "const_int_operand" "n")))]
-  "GET_MODE_CLASS (GET_MODE (operands[0])) == MODE_INT
-   && GET_MODE_SIZE (GET_MODE (operands[0])) <= 4
-   && (GET_CODE (operands[0]) != MEM || ! MEM_VOLATILE_P (operands[0]))"
+  "GET_CODE (operands[0]) != MEM || ! MEM_VOLATILE_P (operands[0])"
   "*
 {
   unsigned int mask;
@@ -3028,17 +3064,6 @@
 
   return AS2 (test%L1,%0,%1);
 }")
-*/
-(define_insn ""
-  [(set (cc0) (zero_extract (match_operand:SI 0 "register_operand" "r")
-			    (const_int 1)
-			    (match_operand:SI 1 "general_operand" "r")))]
-  "GET_CODE (operands[1]) != CONST_INT"
-  "*
-{
-  cc_status.flags |= CC_Z_IN_NOT_C;
-  return AS2 (bt%L0,%1,%0);
-}")
 
 ;; Store-flag instructions.
 
-- 
2.30.2