MIPS: microMIPS: Optimise 'memset' core library function.

Optimise 'memset' to use microMIPS instructions and/or optimisations
for binary size reduction. When the microMIPS ISA is not being used,
the library function compiles to the original binary code.

Signed-off-by: Steven J. Hill <Steven.Hill@imgtec.com>

diff --git a/arch/mips/include/asm/asm.h b/arch/mips/include/asm/asm.h
index 164a21e..879691d 100644 (file)
--- a/arch/mips/include/asm/asm.h
+++ b/arch/mips/include/asm/asm.h
@@ -296,6 +296,7 @@ symbol              =       value
 #define LONG_SUBU      subu
 #define LONG_L         lw
 #define LONG_S         sw
+#define LONG_SP                swp
 #define LONG_SLL       sll
 #define LONG_SLLV      sllv
 #define LONG_SRL       srl
@@ -318,6 +319,7 @@ symbol              =       value
 #define LONG_SUBU      dsubu
 #define LONG_L         ld
 #define LONG_S         sd
+#define LONG_SP                sdp
 #define LONG_SLL       dsll
 #define LONG_SLLV      dsllv
 #define LONG_SRL       dsrl

diff --git a/arch/mips/lib/memset.S b/arch/mips/lib/memset.S
index 053d3b0..0580194 100644 (file)
--- a/arch/mips/lib/memset.S
+++ b/arch/mips/lib/memset.S
@@ -5,7 +5,8 @@
  *
  * Copyright (C) 1998, 1999, 2000 by Ralf Baechle
  * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
- * Copyright (C) 2007  Maciej W. Rozycki
+ * Copyright (C) 2007 by Maciej W. Rozycki
+ * Copyright (C) 2011, 2012 MIPS Technologies, Inc.
  */
 #include <asm/asm.h>
 #include <asm/asm-offsets.h>
@@ -19,6 +20,20 @@
 #define LONG_S_R sdr
 #endif
 
+#ifdef CONFIG_CPU_MICROMIPS
+#define STORSIZE (LONGSIZE * 2)
+#define STORMASK (STORSIZE - 1)
+#define FILL64RG t8
+#define FILLPTRG t7
+#undef  LONG_S
+#define LONG_S LONG_SP
+#else
+#define STORSIZE LONGSIZE
+#define STORMASK LONGMASK
+#define FILL64RG a1
+#define FILLPTRG t0
+#endif
+
 #define EX(insn,reg,addr,handler)                      \
 9:     insn    reg, addr;                              \
        .section __ex_table,"a";                        \
@@ -26,23 +41,25 @@
        .previous
 
        .macro  f_fill64 dst, offset, val, fixup
-       EX(LONG_S, \val, (\offset +  0 * LONGSIZE)(\dst), \fixup)
-       EX(LONG_S, \val, (\offset +  1 * LONGSIZE)(\dst), \fixup)
-       EX(LONG_S, \val, (\offset +  2 * LONGSIZE)(\dst), \fixup)
-       EX(LONG_S, \val, (\offset +  3 * LONGSIZE)(\dst), \fixup)
-       EX(LONG_S, \val, (\offset +  4 * LONGSIZE)(\dst), \fixup)
-       EX(LONG_S, \val, (\offset +  5 * LONGSIZE)(\dst), \fixup)
-       EX(LONG_S, \val, (\offset +  6 * LONGSIZE)(\dst), \fixup)
-       EX(LONG_S, \val, (\offset +  7 * LONGSIZE)(\dst), \fixup)
-#if LONGSIZE == 4
-       EX(LONG_S, \val, (\offset +  8 * LONGSIZE)(\dst), \fixup)
-       EX(LONG_S, \val, (\offset +  9 * LONGSIZE)(\dst), \fixup)
-       EX(LONG_S, \val, (\offset + 10 * LONGSIZE)(\dst), \fixup)
-       EX(LONG_S, \val, (\offset + 11 * LONGSIZE)(\dst), \fixup)
-       EX(LONG_S, \val, (\offset + 12 * LONGSIZE)(\dst), \fixup)
-       EX(LONG_S, \val, (\offset + 13 * LONGSIZE)(\dst), \fixup)
-       EX(LONG_S, \val, (\offset + 14 * LONGSIZE)(\dst), \fixup)
-       EX(LONG_S, \val, (\offset + 15 * LONGSIZE)(\dst), \fixup)
+       EX(LONG_S, \val, (\offset +  0 * STORSIZE)(\dst), \fixup)
+       EX(LONG_S, \val, (\offset +  1 * STORSIZE)(\dst), \fixup)
+       EX(LONG_S, \val, (\offset +  2 * STORSIZE)(\dst), \fixup)
+       EX(LONG_S, \val, (\offset +  3 * STORSIZE)(\dst), \fixup)
+#if ((defined(CONFIG_CPU_MICROMIPS) && (LONGSIZE == 4)) || !defined(CONFIG_CPU_MICROMIPS))
+       EX(LONG_S, \val, (\offset +  4 * STORSIZE)(\dst), \fixup)
+       EX(LONG_S, \val, (\offset +  5 * STORSIZE)(\dst), \fixup)
+       EX(LONG_S, \val, (\offset +  6 * STORSIZE)(\dst), \fixup)
+       EX(LONG_S, \val, (\offset +  7 * STORSIZE)(\dst), \fixup)
+#endif
+#if (!defined(CONFIG_CPU_MICROMIPS) && (LONGSIZE == 4))
+       EX(LONG_S, \val, (\offset +  8 * STORSIZE)(\dst), \fixup)
+       EX(LONG_S, \val, (\offset +  9 * STORSIZE)(\dst), \fixup)
+       EX(LONG_S, \val, (\offset + 10 * STORSIZE)(\dst), \fixup)
+       EX(LONG_S, \val, (\offset + 11 * STORSIZE)(\dst), \fixup)
+       EX(LONG_S, \val, (\offset + 12 * STORSIZE)(\dst), \fixup)
+       EX(LONG_S, \val, (\offset + 13 * STORSIZE)(\dst), \fixup)
+       EX(LONG_S, \val, (\offset + 14 * STORSIZE)(\dst), \fixup)
+       EX(LONG_S, \val, (\offset + 15 * STORSIZE)(\dst), \fixup)
 #endif
        .endm
 
@@ -71,16 +88,20 @@ LEAF(memset)
 1:
 
 FEXPORT(__bzero)
-       sltiu           t0, a2, LONGSIZE        /* very small region? */
+       sltiu           t0, a2, STORSIZE        /* very small region? */
        bnez            t0, .Lsmall_memset
-        andi           t0, a0, LONGMASK        /* aligned? */
+        andi           t0, a0, STORMASK        /* aligned? */
 
+#ifdef CONFIG_CPU_MICROMIPS
+       move            t8, a1                  /* used by 'swp' instruction */
+       move            t9, a1
+#endif
 #ifndef CONFIG_CPU_DADDI_WORKAROUNDS
        beqz            t0, 1f
-        PTR_SUBU       t0, LONGSIZE            /* alignment in bytes */
+        PTR_SUBU       t0, STORSIZE            /* alignment in bytes */
 #else
        .set            noat
-       li              AT, LONGSIZE
+       li              AT, STORSIZE
        beqz            t0, 1f
         PTR_SUBU       t0, AT                  /* alignment in bytes */
        .set            at
@@ -99,24 +120,27 @@ FEXPORT(__bzero)
 1:     ori             t1, a2, 0x3f            /* # of full blocks */
        xori            t1, 0x3f
        beqz            t1, .Lmemset_partial    /* no block to fill */
-        andi           t0, a2, 0x40-LONGSIZE
+        andi           t0, a2, 0x40-STORSIZE
 
        PTR_ADDU        t1, a0                  /* end address */
        .set            reorder
 1:     PTR_ADDIU       a0, 64
        R10KCBARRIER(0(ra))
-       f_fill64 a0, -64, a1, .Lfwd_fixup
+       f_fill64 a0, -64, FILL64RG, .Lfwd_fixup
        bne             t1, a0, 1b
        .set            noreorder
 
 .Lmemset_partial:
        R10KCBARRIER(0(ra))
        PTR_LA          t1, 2f                  /* where to start */
+#ifdef CONFIG_CPU_MICROMIPS
+       LONG_SRL        t7, t0, 1
+#endif
 #if LONGSIZE == 4
-       PTR_SUBU        t1, t0
+       PTR_SUBU        t1, FILLPTRG
 #else
        .set            noat
-       LONG_SRL                AT, t0, 1
+       LONG_SRL        AT, FILLPTRG, 1
        PTR_SUBU        t1, AT
        .set            at
 #endif
@@ -126,9 +150,9 @@ FEXPORT(__bzero)
        .set            push
        .set            noreorder
        .set            nomacro
-       f_fill64 a0, -64, a1, .Lpartial_fixup   /* ... but first do longs ... */
+       f_fill64 a0, -64, FILL64RG, .Lpartial_fixup     /* ... but first do longs ... */
 2:     .set            pop
-       andi            a2, LONGMASK            /* At most one long to go */
+       andi            a2, STORMASK            /* At most one long to go */
 
        beqz            a2, 1f
         PTR_ADDU       a0, a2                  /* What's left */
@@ -169,7 +193,7 @@ FEXPORT(__bzero)
 
 .Lpartial_fixup:
        PTR_L           t0, TI_TASK($28)
-       andi            a2, LONGMASK
+       andi            a2, STORMASK
        LONG_L          t0, THREAD_BUADDR(t0)
        LONG_ADDU       a2, t1
        jr              ra
@@ -177,4 +201,4 @@ FEXPORT(__bzero)
 
 .Llast_fixup:
        jr              ra
-        andi           v1, a2, LONGMASK
+        andi           v1, a2, STORMASK