arch/sh/lib64/memset.S

   1 /* Cloned and hacked for uClibc by Paul Mundt, December 2003 */
   2 /* Modified by SuperH, Inc. September 2003 */
   3 !
   4 ! Fast SH memset
   5 !
   6 ! by Toshiyasu Morita (tm@netcom.com)
   7 !
   8 ! SH5 code by J"orn Rennecke (joern.rennecke@superh.com)
   9 ! Copyright 2002 SuperH Ltd.
  10 !
  11
  12 #if __BYTE_ORDER == __LITTLE_ENDIAN
  13 #define SHHI shlld
  14 #define SHLO shlrd
  15 #else
  16 #define SHHI shlrd
  17 #define SHLO shlld
  18 #endif
  19
  20         .section .text..SHmedia32,"ax"
  21         .globl  memset
  22         .type   memset, @function
  23
  24         .align 5
  25
  26 memset:
  27         pta/l multiquad, tr0
  28         andi r2, 7, r22
  29         ptabs r18, tr2
  30         mshflo.b r3,r3,r3
  31         add r4, r22, r23
  32         mperm.w r3, r63, r3     // Fill pattern now in every byte of r3
  33
  34         movi 8, r9
  35         bgtu/u r23, r9, tr0 // multiquad
  36
  37         beqi/u r4, 0, tr2       // Return with size 0 - ensures no mem accesses
  38         ldlo.q r2, 0, r7
  39         shlli r4, 2, r4
  40         movi -1, r8
  41         SHHI r8, r4, r8
  42         SHHI r8, r4, r8
  43         mcmv r7, r8, r3
  44         stlo.q r2, 0, r3
  45         blink tr2, r63
  46
  47 multiquad:
  48         pta/l lastquad, tr0
  49         stlo.q r2, 0, r3
  50         shlri r23, 3, r24
  51         add r2, r4, r5
  52         beqi/u r24, 1, tr0 // lastquad
  53         pta/l loop, tr1
  54         sub r2, r22, r25
  55         andi r5, -8, r20   // calculate end address and
  56         addi r20, -7*8, r8 // loop end address; This might overflow, so we need
  57                            // to use a different test before we start the loop
  58         bge/u r24, r9, tr1 // loop
  59         st.q r25, 8, r3
  60         st.q r20, -8, r3
  61         shlri r24, 1, r24
  62         beqi/u r24, 1, tr0 // lastquad
  63         st.q r25, 16, r3
  64         st.q r20, -16, r3
  65         beqi/u r24, 2, tr0 // lastquad
  66         st.q r25, 24, r3
  67         st.q r20, -24, r3
  68 lastquad:
  69         sthi.q r5, -1, r3
  70         blink tr2,r63
  71
  72 loop:
  73 !!!     alloco r25, 32  // QQQ comment out for short-term fix to SHUK #3895.
  74                         // QQQ commenting out is locically correct, but sub-optimal
  75                         // QQQ Sean McGoogan - 4th April 2003.
  76         st.q r25, 8, r3
  77         st.q r25, 16, r3
  78         st.q r25, 24, r3
  79         st.q r25, 32, r3
  80         addi r25, 32, r25
  81         bgeu/l r8, r25, tr1 // loop
  82
  83         st.q r20, -40, r3
  84         st.q r20, -32, r3
  85         st.q r20, -24, r3
  86         st.q r20, -16, r3
  87         st.q r20, -8, r3
  88         sthi.q r5, -1, r3
  89         blink tr2,r63
  90
  91         .size   memset,.-memset