[PATCH, ARM] Improve thumb2_extendXXdi2

[Richard Earnshaw <Richard dot Earnshaw at buzzard dot freeserve dot co dot uk>]

This patch improves the code slightly for sign-extend to DImode when
compiling for thumb2.

R.

2009-05-31  Richard Earnshaw  <rearnsha@arm.com>

	* arm/thumb2.md (thumb2_extendsidi2): Add a split sub-pattern.
	(thumb2_extendqidi2): New pattern.


*** ./thumb2.md	(revision 148020)
--- ./thumb2.md	(local)
*************** (define_insn_and_split "*thumb2_zero_ext
*** 895,918 ****
     (set_attr "neg_pool_range" "*,250")]
  )
  
! (define_insn "*thumb2_extendsidi2"
    [(set (match_operand:DI 0 "s_register_operand" "=r")
          (sign_extend:DI (match_operand:SI 1 "s_register_operand" "r")))]
    "TARGET_THUMB2"
!   "*
!     /* ??? Output both instructions unconditionally, otherwise the conditional
!        execution insn counter gets confused.
!     if (REGNO (operands[1])
!         != REGNO (operands[0]) + (WORDS_BIG_ENDIAN ? 1 : 0)) */
!       output_asm_insn (\"mov%?\\t%Q0, %1\", operands);
!     return \"asr%?\\t%R0, %Q0, #31\";
!   "
    [(set_attr "length" "8")
     (set_attr "ce_count" "2")
     (set_attr "shift" "1")
     (set_attr "predicable" "yes")]
  )
  
  ;; All supported Thumb2 implementations are armv6, so only that case is
  ;; provided.
  (define_insn "*thumb2_extendqisi_v6"
--- 895,944 ----
     (set_attr "neg_pool_range" "*,250")]
  )
  
! (define_insn_and_split "*thumb2_extendsidi2"
    [(set (match_operand:DI 0 "s_register_operand" "=r")
          (sign_extend:DI (match_operand:SI 1 "s_register_operand" "r")))]
    "TARGET_THUMB2"
!   "mov%?\\t%Q0, %1\;asr?\\t%R0, %1, #31"
!   "&& reload_completed"
!   [(set (match_dup 0) (ashiftrt:SI (match_dup 1) (const_int 31)))]
!   {
!     rtx lo_part = gen_lowpart (SImode, operands[0]);
! 
!     if (!REG_P (lo_part) || REGNO (lo_part) != REGNO (operands[1]))
!       emit_move_insn (lo_part, operands[1]);
!     operands[0] = gen_highpart (SImode, operands[0]);
!   }
    [(set_attr "length" "8")
     (set_attr "ce_count" "2")
     (set_attr "shift" "1")
     (set_attr "predicable" "yes")]
  )
  
+ (define_insn_and_split "*thumb2_extendqidi2"
+   [(set (match_operand:DI                 0 "s_register_operand"  "=r,r")
+ 	(sign_extend:DI (match_operand:QI 1 "nonimmediate_operand" "r,m")))]
+   "TARGET_THUMB2"
+   "@
+    sxtb%?\\t%Q0, %1\;asr%?\\t%R0, %Q0, #31
+    ldrsb%?\\t%Q0, %1\;asr%?\\t%R0, %Q0, #31"
+   "&& reload_completed"
+   [(set (match_dup 0) (sign_extend:SI (match_dup 1)))
+    (set (match_dup 2) (ashiftrt:SI (match_dup 0) (const_int 31)))]
+   "
+   {
+     operands[2] = gen_highpart (SImode, operands[0]);
+     operands[0] = gen_lowpart (SImode, operands[0]);
+   }
+   "
+   [(set_attr "length" "8")
+    (set_attr "ce_count" "2")
+    (set_attr "predicable" "yes")
+    (set_attr "type" "*,load_byte")
+    (set_attr "pool_range" "*,4092")
+    (set_attr "neg_pool_range" "*,250")]
+ )
+ 
  ;; All supported Thumb2 implementations are armv6, so only that case is
  ;; provided.
  (define_insn "*thumb2_extendqisi_v6"