Unroll my commit of 1999/08/01 16:14:58, there was a communications mixup

about its status.

From-SVN: r28403

gcc/ChangeLog

@@ -36,44 +36,6 @@ Sun Aug  1 20:14:00 1999  Bernd Schmidt  <bernds@cygnus.co.uk>
 
 	* tree.h (init_dummy_function_start): Declare.
 
-Sun Jul 25 19:32:58 1999  Geoff Keating  <geoffk@cygnus.com>
-
-	* config/rs6000/rs6000.c (num_insns_constant_wide): Correct
-	for type promotion.
-	(add_operand): Get test correct for 64-bit HOST_WIDE_INT.
-	(non_add_cint_operand): Likewise.
-	(logical_operand): Likewise.
-	(non_logical_cint_operand): Likewise.
-	(print_operand): Correct printf()s for 64-bit HOST_WIDE_INT.
-	(print_operand_address): Correct printf() for 64-bit HOST_WIDE_INT.
-	(rs6000_select_rtx_section): Suppress warning.
-	(small_data_operand): Suppress warning.
-	(rs6000_got_register): Suppress warning.
-	* config/rs6000/rs6000.md (andsi3): HOST_WIDE_INT is a signed
-	type, so `J' is generally the wrong constraint for a SImode value;
-	use `L' instead.
-	(andsi3_internal2): Likewise.
-	(andsi3_internal3): Likewise.
-	(iorsi3_internal1): Likewise.
-	(xorsi3_internal1): Likewise.
-	(movsi): Likewise.
-	(movsf_softfloat): Likewise.
-	various unnamed compare insns: Likewise.
-	(movsi+2): Preserve sign bits of SImode constant.
-	(floatsidf2_internal+1): Sign-extend SImode constant correctly.
-	(movdf+1): Preserve high bits of DFmode constant.
-	(movdi_32+1): Sign-extend properly.
-	various unnamed compare insns: Sign-extend properly.
-
-	* unroll.c (loop_iterations): Convert HOST_WIDE_INT to unsigned
-	properly for mode.
-	* expmed.c (expand_mult_highpart): Convert HOST_WIDE_INT from unsigned
-	properly for mode.
-	(expand_divmod): Likewise.
-	* optabs.c (expand_fix): Keep HOST_WIDE_INT constants properly signed.
-	(expand_binop): Sometimes there is work to do when changing
-	the mode of a CONST_INT.
-
 Sun Aug  1 12:55:31 1999  Bernd Schmidt  <bernds@cygnus.co.uk>
 
 	* stmt.c (emit_filename, emit_lineno, expr_stmts_for_value,

gcc/config/rs6000/rs6000.c

@@ -666,11 +666,16 @@ num_insns_constant_wide (value)
   if (((unsigned HOST_WIDE_INT)value + 0x8000) < 0x10000)
     return 1;
 
+#if HOST_BITS_PER_WIDE_INT == 32
+  /* constant loadable with {cau|addis} */
+  else if ((value & 0xffff) == 0)
+    return 1;
+
+#else
   /* constant loadable with {cau|addis} */
-  else if (CONST_OK_FOR_LETTER_P (value, 'L'))
+  else if ((value & 0xffff) == 0 && (value & ~0xffffffff) == 0)
     return 1;
 
-#if HOST_BITS_PER_WIDE_INT == 64
   else if (TARGET_64BIT)
     {
       HOST_WIDE_INT low  = value & 0xffffffff;
@@ -875,7 +880,7 @@ mem_or_easy_const_operand (op, mode)
 }
 
 /* Return 1 if the operand is either a non-special register or an item
-   that can be used as the operand of a `mode' add insn.  */
+   that can be used as the operand of an SI add insn.  */
 
 int
 add_operand (op, mode)
@@ -884,7 +889,7 @@ add_operand (op, mode)
 {
   return (reg_or_short_operand (op, mode)
 	  || (GET_CODE (op) == CONST_INT
-	      && CONST_OK_FOR_LETTER_P (INTVAL(op), 'L')));
+	      && (INTVAL (op) & (~ (HOST_WIDE_INT) 0xffff0000)) == 0));
 }
 
 /* Return 1 if OP is a constant but not a valid add_operand.  */
@@ -896,7 +901,7 @@ non_add_cint_operand (op, mode)
 {
   return (GET_CODE (op) == CONST_INT
 	  && (unsigned HOST_WIDE_INT) (INTVAL (op) + 0x8000) >= 0x10000
-	  && ! CONST_OK_FOR_LETTER_P (INTVAL(op), 'L'));
+	  && (INTVAL (op) & (~ (HOST_WIDE_INT) 0xffff0000)) != 0);
 }
 
 /* Return 1 if the operand is a non-special register or a constant that
@@ -909,10 +914,8 @@ logical_operand (op, mode)
 {
   return (gpc_reg_operand (op, mode)
 	  || (GET_CODE (op) == CONST_INT
-	      && ((INTVAL (op) & GET_MODE_MASK (mode)
-		   & (~ (HOST_WIDE_INT) 0xffff)) == 0
-		  || (INTVAL (op) & GET_MODE_MASK (mode)
-		      & (~ (HOST_WIDE_INT) 0xffff0000)) == 0)));
+	      && ((INTVAL (op) & (~ (HOST_WIDE_INT) 0xffff)) == 0
+		  || (INTVAL (op) & (~ (HOST_WIDE_INT) 0xffff0000)) == 0)));
 }
 
 /* Return 1 if C is a constant that is not a logical operand (as
@@ -921,13 +924,11 @@ logical_operand (op, mode)
 int
 non_logical_cint_operand (op, mode)
      register rtx op;
-     enum machine_mode mode;
+     enum machine_mode mode ATTRIBUTE_UNUSED;
 {
   return (GET_CODE (op) == CONST_INT
-	  && (INTVAL (op) & GET_MODE_MASK (mode) &
-	      (~ (HOST_WIDE_INT) 0xffff)) != 0
-	  && (INTVAL (op) & GET_MODE_MASK (mode) &
-	      (~ (HOST_WIDE_INT) 0xffff0000)) != 0);
+	  && (INTVAL (op) & (~ (HOST_WIDE_INT) 0xffff)) != 0
+	  && (INTVAL (op) & (~ (HOST_WIDE_INT) 0xffff0000)) != 0);
 }
 
 /* Return 1 if C is a constant that can be encoded in a 32-bit mask on the
@@ -1197,7 +1198,7 @@ small_data_operand (op, mode)
      enum machine_mode mode ATTRIBUTE_UNUSED;
 {
 #if TARGET_ELF
-  rtx sym_ref;
+  rtx sym_ref, const_part;
 
   if (rs6000_sdata == SDATA_NONE || rs6000_sdata == SDATA_DATA)
     return 0;
@@ -2473,7 +2474,7 @@ ccr_bit (op, scc_p)
 
 struct rtx_def *
 rs6000_got_register (value)
-     rtx value ATTRIBUTE_UNUSED;
+     rtx value;
 {
   /* The second flow pass currently (June 1999) can't update regs_ever_live
      without disturbing other parts of the compiler, so update it here to
@@ -2626,7 +2627,7 @@ print_operand (file, x, code)
       if (! INT_P (x))
 	output_operand_lossage ("invalid %%b value");
 
-      fprintf (file, HOST_WIDE_INT_PRINT_DEC, INT_LOWPART (x) & 0xffff);
+      fprintf (file, "%d", INT_LOWPART (x) & 0xffff);
       return;
 
     case 'B':
@@ -2712,7 +2713,7 @@ print_operand (file, x, code)
       /* If constant, output low-order five bits.  Otherwise,
 	 write normally. */
       if (INT_P (x))
-	fprintf (file, HOST_WIDE_INT_PRINT_DEC, INT_LOWPART (x) & 31);
+	fprintf (file, "%d", INT_LOWPART (x) & 31);
       else
 	print_operand (file, x, 0);
       return;
@@ -2721,7 +2722,7 @@ print_operand (file, x, code)
       /* If constant, output low-order six bits.  Otherwise,
 	 write normally. */
       if (INT_P (x))
-	fprintf (file, HOST_WIDE_INT_PRINT_DEC, INT_LOWPART (x) & 63);
+	fprintf (file, "%d", INT_LOWPART (x) & 63);
       else
 	print_operand (file, x, 0);
       return;
@@ -2758,7 +2759,7 @@ print_operand (file, x, code)
       if (! INT_P (x))
 	output_operand_lossage ("invalid %%k value");
 
-      fprintf (file, HOST_WIDE_INT_PRINT_DEC, ~ INT_LOWPART (x));
+      fprintf (file, "%d", ~ INT_LOWPART (x));
       return;
 
     case 'L':
@@ -2902,7 +2903,7 @@ print_operand (file, x, code)
       if (! INT_P (x))
 	output_operand_lossage ("invalid %%s value");
 
-      fprintf (file, HOST_WIDE_INT_PRINT_DEC, (32 - INT_LOWPART (x)) & 31);
+      fprintf (file, "%d", (32 - INT_LOWPART (x)) & 31);
       return;
 
     case 'S':
@@ -3005,8 +3006,7 @@ print_operand (file, x, code)
       if (! INT_P (x))
 	output_operand_lossage ("invalid %%u value");
 
-      fprintf (file, HOST_WIDE_INT_PRINT_HEX, 
-	       (INT_LOWPART (x) >> 16) & 0xffff);
+      fprintf (file, "0x%x", (INT_LOWPART (x) >> 16) & 0xffff);
       return;
 
     case 'v':
@@ -3076,8 +3076,7 @@ print_operand (file, x, code)
       /* If constant, low-order 16 bits of constant, signed.  Otherwise, write
 	 normally.  */
       if (INT_P (x))
-	fprintf (file, HOST_WIDE_INT_PRINT_DEC, 
-		 ((INT_LOWPART (x) & 0xffff) ^ 0x8000) - 0x8000);
+	fprintf (file, "%d", ((INT_LOWPART (x) & 0xffff) ^ 0x8000) - 0x8000);
       else
 	print_operand (file, x, 0);
       return;
@@ -3086,7 +3085,7 @@ print_operand (file, x, code)
       /* If constant, low-order 16 bits of constant, unsigned.
 	 Otherwise, write normally.  */
       if (INT_P (x))
-	fprintf (file, HOST_WIDE_INT_PRINT_DEC, INT_LOWPART (x) & 0xffff);
+	fprintf (file, "%d", INT_LOWPART (x) & 0xffff);
       else
 	print_operand (file, x, 0);
       return;
@@ -3222,10 +3221,7 @@ print_operand_address (file, x)
 		 reg_names[ REGNO (XEXP (x, 1)) ]);
     }
   else if (GET_CODE (x) == PLUS && GET_CODE (XEXP (x, 1)) == CONST_INT)
-    {
-      fprintf (file, HOST_WIDE_INT_PRINT_DEC, INTVAL (XEXP (x, 1)));
-      fprintf (file, "(%s)", reg_names[ REGNO (XEXP (x, 0)) ]);
-    }
+    fprintf (file, "%d(%s)", INTVAL (XEXP (x, 1)), reg_names[ REGNO (XEXP (x, 0)) ]);
 #if TARGET_ELF
   else if (GET_CODE (x) == LO_SUM && GET_CODE (XEXP (x, 0)) == REG
            && CONSTANT_P (XEXP (x, 1)))
@@ -5653,7 +5649,7 @@ rs6000_longcall_ref (call_ref)
 
 void
 rs6000_select_rtx_section (mode, x)
-     enum machine_mode mode ATTRIBUTE_UNUSED;
+     enum machine_mode mode;
      rtx x;
 {
   if (ASM_OUTPUT_SPECIAL_POOL_ENTRY_P (x))

gcc/config/rs6000/rs6000.md

@@ -1938,7 +1938,7 @@
 (define_insn "andsi3"
   [(set (match_operand:SI 0 "gpc_reg_operand" "=r,r,r,r")
 	(and:SI (match_operand:SI 1 "gpc_reg_operand" "%r,r,r,r")
-		(match_operand:SI 2 "and_operand" "?r,T,K,L")))
+		(match_operand:SI 2 "and_operand" "?r,T,K,J")))
    (clobber (match_scratch:CC 3 "=X,X,x,x"))]
   ""
   "@
@@ -1955,7 +1955,7 @@
 (define_insn "*andsi3_internal2"
   [(set (match_operand:CC 0 "cc_reg_operand" "=x,x,x,x,?y,??y,??y,?y")
 	(compare:CC (and:SI (match_operand:SI 1 "gpc_reg_operand" "%r,r,r,r,r,r,r,r")
-			    (match_operand:SI 2 "and_operand" "r,K,L,T,r,K,L,T"))
+			    (match_operand:SI 2 "and_operand" "r,K,J,T,r,K,J,T"))
 		    (const_int 0)))
    (clobber (match_scratch:SI 3 "=r,r,r,r,r,r,r,r"))
    (clobber (match_scratch:CC 4 "=X,X,X,X,X,x,x,X"))]
@@ -1992,7 +1992,7 @@
 (define_insn "*andsi3_internal3"
   [(set (match_operand:CC 3 "cc_reg_operand" "=x,x,x,x,?y,??y,??y,?y")
 	(compare:CC (and:SI (match_operand:SI 1 "gpc_reg_operand" "%r,r,r,r,r,r,r,r")
-			    (match_operand:SI 2 "and_operand" "r,K,L,T,r,K,L,T"))
+			    (match_operand:SI 2 "and_operand" "r,K,J,T,r,K,J,T"))
 		    (const_int 0)))
    (set (match_operand:SI 0 "gpc_reg_operand" "=r,r,r,r,r,r,r,r")
 	(and:SI (match_dup 1)
@@ -2054,7 +2054,7 @@
 (define_insn "*iorsi3_internal1"
   [(set (match_operand:SI 0 "gpc_reg_operand" "=r,r,r")
 	(ior:SI (match_operand:SI 1 "gpc_reg_operand" "%r,r,r")
-		(match_operand:SI 2 "logical_operand" "r,K,L")))]
+		(match_operand:SI 2 "logical_operand" "r,K,J")))]
   ""
   "@
    or %0,%1,%2
@@ -2161,7 +2161,7 @@
 (define_insn "*xorsi3_internal1"
   [(set (match_operand:SI 0 "gpc_reg_operand" "=r,r,r")
 	(xor:SI (match_operand:SI 1 "gpc_reg_operand" "%r,r,r")
-		(match_operand:SI 2 "logical_operand" "r,K,L")))]
+		(match_operand:SI 2 "logical_operand" "r,K,J")))]
   ""
   "@
    xor %0,%1,%2
@@ -4226,7 +4226,7 @@
 		  (match_dup 3)))]
   "
 {
-  operands[6] = GEN_INT (~ (HOST_WIDE_INT) 0x7fffffff);
+  operands[6] = GEN_INT (0x80000000);
   operands[7] = gen_rtx_REG (DFmode, FPMEM_REGNUM);
 }")
 
@@ -6127,7 +6127,7 @@
 		(match_dup 3)))]
   "
 {
-  operands[2] = GEN_INT (INTVAL (operands[1]) & (~ (HOST_WIDE_INT) 0xffff));
+  operands[2] = GEN_INT (INTVAL (operands[1]) & 0xffff0000);
   operands[3] = GEN_INT (INTVAL (operands[1]) & 0xffff);
 }")
 
@@ -6383,7 +6383,7 @@
   int endian = (WORDS_BIG_ENDIAN == 0);
   operands[2] = operand_subword (operands[0], endian, 0, DFmode);
   operands[3] = operand_subword (operands[0], 1 - endian, 0, DFmode);
-  operands[4] = GEN_INT(INTVAL (operands[1]) >> 31 >> 1);
+  operands[4] = (INTVAL (operands[1]) & 0x80000000) ? constm1_rtx : const0_rtx;
 }")
 
 (define_split
@@ -6740,14 +6740,13 @@
    (set (match_dup 3) (match_dup 1))]
   "
 {
-  HOST_WIDE_INT value = INTVAL (operands[1]);
   operands[2] = gen_rtx_SUBREG (SImode, operands[0], WORDS_BIG_ENDIAN == 0);
   operands[3] = gen_rtx_SUBREG (SImode, operands[0], WORDS_BIG_ENDIAN != 0);
 #if HOST_BITS_PER_WIDE_INT == 32
-  operands[4] = (value & 0x80000000) ? constm1_rtx : const0_rtx;
+  operands[4] = (INTVAL (operands[1]) & 0x80000000) ? constm1_rtx : const0_rtx;
 #else
-  operands[4] = GEN_INT (value >> 32);
-  operands[1] = GEN_INT ((value & 0x7fffffff) - (value & 0x80000000));
+  operands[4] = GEN_INT ((HOST_WIDE_INT) INTVAL (operands[1]) >> 32);
+  operands[1] = GEN_INT (INTVAL (operands[1]) & 0xffffffff);
 #endif
 }")
 
@@ -8894,9 +8893,9 @@
      sign-extended to 16 bits.  Then see what constant could be XOR'ed
      with C to get the sign-extended value.  */
 
-  HOST_WIDE_INT c = INTVAL (operands[2]);
-  HOST_WIDE_INT sextc = (c & 0x7fff) - (c & 0x8000);
-  HOST_WIDE_INT xorv = c ^ sextc;
+  int c = INTVAL (operands[2]);
+  int sextc = (c << 16) >> 16;
+  int xorv = c ^ sextc;
 
   operands[4] = GEN_INT (xorv);
   operands[5] = GEN_INT (sextc);
@@ -9129,7 +9128,7 @@
 (define_insn ""
   [(set (match_operand:SI 0 "gpc_reg_operand" "=r,r,r,r,r")
 	(eq:SI (match_operand:SI 1 "gpc_reg_operand" "%r,r,r,r,r")
-	       (match_operand:SI 2 "reg_or_cint_operand" "r,O,K,L,I")))
+	       (match_operand:SI 2 "reg_or_cint_operand" "r,O,K,J,I")))
    (clobber (match_scratch:SI 3 "=r,&r,r,r,r"))]
   ""
   "@
@@ -9158,7 +9157,7 @@
   [(set (match_operand:CC 4 "cc_reg_operand" "=x,x,x,x,x")
 	(compare:CC
 	 (eq:SI (match_operand:SI 1 "gpc_reg_operand" "%r,r,r,r,r")
-		(match_operand:SI 2 "reg_or_cint_operand" "r,O,K,L,I"))
+		(match_operand:SI 2 "reg_or_cint_operand" "r,O,K,J,I"))
 	 (const_int 0)))
    (set (match_operand:SI 0 "gpc_reg_operand" "=r,r,r,r,r")
 	(eq:SI (match_dup 1) (match_dup 2)))
@@ -9210,7 +9209,7 @@
 (define_insn ""
   [(set (match_operand:SI 0 "gpc_reg_operand" "=r,r,r,r,r")
 	(plus:SI (eq:SI (match_operand:SI 1 "gpc_reg_operand" "%r,r,r,r,r")
-			(match_operand:SI 2 "reg_or_cint_operand" "r,O,K,L,I"))
+			(match_operand:SI 2 "reg_or_cint_operand" "r,O,K,J,I"))
 		 (match_operand:SI 3 "gpc_reg_operand" "r,r,r,r,r")))
    (clobber (match_scratch:SI 4 "=&r,&r,&r,&r,&r"))]
   ""
@@ -9227,7 +9226,7 @@
 	(compare:CC
 	 (plus:SI
 	  (eq:SI (match_operand:SI 1 "gpc_reg_operand" "%r,r,r,r,r")
-		 (match_operand:SI 2 "reg_or_cint_operand" "r,O,K,L,I"))
+		 (match_operand:SI 2 "reg_or_cint_operand" "r,O,K,J,I"))
 	  (match_operand:SI 3 "gpc_reg_operand" "r,r,r,r,r"))
 	 (const_int 0)))
    (clobber (match_scratch:SI 4 "=&r,&r,&r,&r,&r"))]
@@ -9246,7 +9245,7 @@
 	(compare:CC
 	 (plus:SI
 	  (eq:SI (match_operand:SI 1 "gpc_reg_operand" "%r,r,r,r,r")
-		 (match_operand:SI 2 "reg_or_cint_operand" "r,O,K,L,I"))
+		 (match_operand:SI 2 "reg_or_cint_operand" "r,O,K,J,I"))
 	  (match_operand:SI 3 "gpc_reg_operand" "r,r,r,r,r"))
 	 (const_int 0)))
    (set (match_operand:SI 0 "gpc_reg_operand" "=r,r,r,r,r")
@@ -9265,7 +9264,7 @@
 (define_insn ""
   [(set (match_operand:SI 0 "gpc_reg_operand" "=r,r,r,r,r")
 	(neg:SI (eq:SI (match_operand:SI 1 "gpc_reg_operand" "%r,r,r,r,r")
-		       (match_operand:SI 2 "reg_or_cint_operand" "r,O,K,L,I"))))]
+		       (match_operand:SI 2 "reg_or_cint_operand" "r,O,K,J,I"))))]
   ""
   "@
    xor %0,%1,%2\;{ai|addic} %0,%0,-1\;{sfe|subfe} %0,%0,%0

gcc/expmed.c

@@ -2718,13 +2718,13 @@ expand_mult_highpart (mode, op0, cnst1, target, unsignedp, max_cost)
   int size = GET_MODE_BITSIZE (mode);
   rtx op1, wide_op1;
 
-  /* We can't support modes wider than HOST_BITS_PER_WIDE_INT.  */
+  /* We can't support modes wider than HOST_BITS_PER_INT.  */
   if (size > HOST_BITS_PER_WIDE_INT)
     abort ();
 
-  op1 = GEN_INT (cnst1 | -(cnst1 & ((HOST_WIDE_INT) 1 << (size - 1))));
+  op1 = GEN_INT (cnst1);
 
-  if (GET_MODE_BITSIZE (wider_mode) <= HOST_BITS_PER_WIDE_INT)
+  if (GET_MODE_BITSIZE (wider_mode) <= HOST_BITS_PER_INT)
     wide_op1 = op1;
   else
     wide_op1
@@ -3726,8 +3726,6 @@ expand_divmod (rem_flag, code, mode, op0, op1, target, unsignedp)
 
 	    post_shift = floor_log2 (d & -d);
 	    ml = invert_mod2n (d >> post_shift, size);
-	    /* Sign-extend ml for compute_mode.  */
-	    ml |= -(ml & (1 << (GET_MODE_BITSIZE (compute_mode)-1)));
 	    t1 = expand_mult (compute_mode, op0, GEN_INT (ml), NULL_RTX,
 			      unsignedp);
 	    quotient = expand_shift (RSHIFT_EXPR, compute_mode, t1,

gcc/md.texi

@@ -1384,14 +1384,13 @@ Floating point register
 Signed 16 bit constant
 
 @item J
-Unsigned 16 bit constant shifted left 16 bits (use @samp{L} instead for 
-@code{SImode} constants)
+Constant whose low 16 bits are 0
 
 @item K
-Unsigned 16 bit constant
+Constant whose high 16 bits are 0
 
 @item L
-Signed 16 bit constant shifted left 16 bits
+Constant suitable as a mask operand
 
 @item M
 Constant larger than 31
@@ -1419,9 +1418,6 @@ AIX TOC entry
 @item S
 Constant suitable as a 64-bit mask operand
 
-@item T
-Constant suitable as a 32-bit mask operand
-
 @item U
 System V Release 4 small data area reference
 @end table

gcc/optabs.c

@@ -857,12 +857,12 @@ expand_binop (mode, binoptab, op0, op1, target, unsignedp, methods)
       /* In case the insn wants input operands in modes different from
 	 the result, convert the operands.  */
 
-      if ((GET_MODE (op0) != VOIDmode || GET_CODE (op0) == CONST_INT)
+      if (GET_MODE (op0) != VOIDmode
 	  && GET_MODE (op0) != mode0
 	  && mode0 != VOIDmode)
 	xop0 = convert_to_mode (mode0, xop0, unsignedp);
 
-      if ((GET_MODE (xop1) != VOIDmode || GET_CODE (xop1) == CONST_INT)
+      if (GET_MODE (xop1) != VOIDmode
 	  && GET_MODE (xop1) != mode1
 	  && mode1 != VOIDmode)
 	xop1 = convert_to_mode (mode1, xop1, unsignedp);
@@ -4231,7 +4231,7 @@ expand_fix (to, from, unsignedp)
 				 NULL_RTX, 0, OPTAB_LIB_WIDEN);
 	  expand_fix (to, target, 0);
 	  target = expand_binop (GET_MODE (to), xor_optab, to,
-				 GEN_INT ((HOST_WIDE_INT) -1 << (bitsize - 1)),
+				 GEN_INT ((HOST_WIDE_INT) 1 << (bitsize - 1)),
 				 to, 1, OPTAB_LIB_WIDEN);
 
 	  if (target != to)

gcc/unroll.c

@@ -3588,7 +3588,6 @@ loop_iterations (loop_start, loop_end, loop_info)
   rtx comparison, comparison_value;
   rtx iteration_var, initial_value, increment, final_value;
   enum rtx_code comparison_code;
-  enum machine_mode comparison_mode;
   HOST_WIDE_INT abs_inc;
   unsigned HOST_WIDE_INT abs_diff;
   int off_by_one;
@@ -3653,7 +3652,6 @@ loop_iterations (loop_start, loop_end, loop_info)
      invariant register when it canonicalizes the comparison.  */
 
   comparison_code = GET_CODE (comparison);
-  comparison_mode = GET_MODE (comparison);
   iteration_var = XEXP (comparison, 0);
   comparison_value = XEXP (comparison, 1);
 
@@ -3993,10 +3991,6 @@ loop_iterations (loop_start, loop_end, loop_info)
   else
     abort ();
 
-  /* It may be that comparison_mode is smaller than a HOST_WIDE_INT,
-     for instance on a 64-bit host when comparison_mode is SImode.  */
-  abs_diff &= GET_MODE_MASK (comparison_mode);
-
   /* For NE tests, make sure that the iteration variable won't miss
      the final value.  If abs_diff mod abs_incr is not zero, then the
      iteration variable will overflow before the loop exits, and we