diff options
Diffstat (limited to 'nuttx/arch/arm/src/armv7-m/memcpy.S')
-rw-r--r-- | nuttx/arch/arm/src/armv7-m/memcpy.S | 351 |
1 files changed, 0 insertions, 351 deletions
diff --git a/nuttx/arch/arm/src/armv7-m/memcpy.S b/nuttx/arch/arm/src/armv7-m/memcpy.S deleted file mode 100644 index c6d3ff649..000000000 --- a/nuttx/arch/arm/src/armv7-m/memcpy.S +++ /dev/null @@ -1,351 +0,0 @@ -@ -@ armv7m-optimised memcpy, apparently in the public domain -@ -@ Obtained via a posting on the Stellaris forum: -@ http://e2e.ti.com/support/microcontrollers/stellaris_arm_cortex-m3_microcontroller/f/473/t/44360.aspx -@ -@ Posted by rocksoft on Jul 24, 2008 10:19 AM -@ -@ Hi, -@ -@ I recently finished a "memcpy" replacement and thought it might be useful for others... -@ -@ I've put some instructions and the code here: -@ -@ http://www.rock-software.net/downloads/memcpy/ -@ -@ Hope it works for you as well as it did for me. -@ -@ Liam. -@ @ -@ ---------------------------------------------------------------------------- - -.syntax unified - -.thumb - -.cpu cortex-m3 - -@ ---------------------------------------------------------------------------- - - .global memcpy - - -@ ---------------------------------------------------------------------------- -@ Optimised "general" copy routine - -.text - -@ We have 16 possible alignment combinations of src and dst, this jump table directs the copy operation -@ Bits: Src=00, Dst=00 - Long to Long copy -@ Bits: Src=00, Dst=01 - Long to Byte before half word -@ Bits: Src=00, Dst=10 - Long to Half word -@ Bits: Src=00, Dst=11 - Long to Byte before long word -@ Bits: Src=01, Dst=00 - Byte before half word to long -@ Bits: Src=01, Dst=01 - Byte before half word to byte before half word - Same alignment -@ Bits: Src=01, Dst=10 - Byte before half word to half word -@ Bits: Src=01, Dst=11 - Byte before half word to byte before long word -@ Bits: Src=10, Dst=00 - Half word to long word -@ Bits: Src=10, Dst=01 - Half word to byte before half word -@ Bits: Src=10, Dst=10 - Half word to half word - Same Alignment -@ Bits: Src=10, Dst=11 - Half word to byte before long word -@ Bits: Src=11, Dst=00 - Byte before long word to long word -@ Bits: Src=11, Dst=01 - Byte before long word to byte before half word -@ Bits: Src=11, Dst=11 - Byte before long word to half word -@ Bits: Src=11, Dst=11 - Byte before long word to Byte before long word - Same alignment - -MEM_DataCopyTable: - .byte (MEM_DataCopy0 - MEM_DataCopyJump) >> 1 - .byte (MEM_DataCopy1 - MEM_DataCopyJump) >> 1 - .byte (MEM_DataCopy2 - MEM_DataCopyJump) >> 1 - .byte (MEM_DataCopy3 - MEM_DataCopyJump) >> 1 - .byte (MEM_DataCopy4 - MEM_DataCopyJump) >> 1 - .byte (MEM_DataCopy5 - MEM_DataCopyJump) >> 1 - .byte (MEM_DataCopy6 - MEM_DataCopyJump) >> 1 - .byte (MEM_DataCopy7 - MEM_DataCopyJump) >> 1 - .byte (MEM_DataCopy8 - MEM_DataCopyJump) >> 1 - .byte (MEM_DataCopy9 - MEM_DataCopyJump) >> 1 - .byte (MEM_DataCopy10 - MEM_DataCopyJump) >> 1 - .byte (MEM_DataCopy11 - MEM_DataCopyJump) >> 1 - .byte (MEM_DataCopy12 - MEM_DataCopyJump) >> 1 - .byte (MEM_DataCopy13 - MEM_DataCopyJump) >> 1 - .byte (MEM_DataCopy14 - MEM_DataCopyJump) >> 1 - .byte (MEM_DataCopy15 - MEM_DataCopyJump) >> 1 - - .align 2 - -@ ---------------------------------------------------------------------------- - -//#define 10 10 - -MEM_LongCopyTable: - .byte (MEM_LongCopyEnd - MEM_LongCopyJump) >> 1 @ 0 bytes left - .byte 0 @ 4 bytes left - .byte (1 * 10) >> 1 @ 8 bytes left - .byte (2 * 10) >> 1 @ 12 bytes left - .byte (3 * 10) >> 1 @ 16 bytes left - .byte (4 * 10) >> 1 @ 20 bytes left - .byte (5 * 10) >> 1 @ 24 bytes left - .byte (6 * 10) >> 1 @ 28 bytes left - .byte (7 * 10) >> 1 @ 32 bytes left - .byte (8 * 10) >> 1 @ 36 bytes left - - .align 2 - -@ ---------------------------------------------------------------------------- -@ r0 = destination, r1 = source, r2 = length - -.thumb_func - -memcpy: - push {r14} - - @ This allows the inner workings to "assume" a minimum amount of bytes - cmp r2, #4 - blt MEM_DataCopyBytes - - and r14, r0, #3 @ Get destination alignment bits - bfi r14, r1, #2, #2 @ Get source alignment bits - ldr r3, =MEM_DataCopyTable @ Jump table base - tbb [r3, r14] @ Perform jump on src/dst alignment bits -MEM_DataCopyJump: - - .align 4 - -@ ---------------------------------------------------------------------------- -@ Bits: Src=01, Dst=01 - Byte before half word to byte before half word - Same alignment -@ 3 bytes to read for long word aligning - -MEM_DataCopy5: - ldrb r3, [r1], #0x01 - strb r3, [r0], #0x01 - sub r2, r2, #0x01 - -@ ---------------------------------------------------------------------------- -@ Bits: Src=10, Dst=10 - Half word to half word - Same Alignment -@ 2 bytes to read for long word aligning - -MEM_DataCopy10: - ldrb r3, [r1], #0x01 - strb r3, [r0], #0x01 - sub r2, r2, #0x01 - -@ ---------------------------------------------------------------------------- -@ Bits: Src=11, Dst=11 - Byte before long word to Byte before long word - Same alignment -@ 1 bytes to read for long word aligning - -MEM_DataCopy15: - ldrb r3, [r1], #0x01 - strb r3, [r0], #0x01 - sub r2, r2, #0x01 - -@ ---------------------------------------------------------------------------- -@ Bits: Src=00, Dst=00 - Long to Long copy - -MEM_DataCopy0: - @ Save regs - push {r4-r12} - - cmp r2, #0x28 - blt MEM_DataCopy0_2 - -MEM_DataCopy0_1: - ldmia r1!, {r3-r12} - stmia r0!, {r3-r12} - sub r2, r2, #0x28 - cmp r2, #0x28 - bge MEM_DataCopy0_1 - -MEM_DataCopy0_2: - @ Copy remaining long words - ldr r14, =MEM_LongCopyTable - lsr r11, r2, #0x02 - tbb [r14, r11] - -MEM_LongCopyJump: - ldr.w r3, [r1], #0x04 @ 4 bytes remain - str.w r3, [r0], #0x04 - b MEM_LongCopyEnd - ldmia.w r1!, {r3-r4} @ 8 bytes remain - stmia.w r0!, {r3-r4} - b MEM_LongCopyEnd - ldmia.w r1!, {r3-r5} @ 12 bytes remain - stmia.w r0!, {r3-r5} - b MEM_LongCopyEnd - ldmia.w r1!, {r3-r6} @ 16 bytes remain - stmia.w r0!, {r3-r6} - b MEM_LongCopyEnd - ldmia.w r1!, {r3-r7} @ 20 bytes remain - stmia.w r0!, {r3-r7} - b MEM_LongCopyEnd - ldmia.w r1!, {r3-r8} @ 24 bytes remain - stmia.w r0!, {r3-r8} - b MEM_LongCopyEnd - ldmia.w r1!, {r3-r9} @ 28 bytes remain - stmia.w r0!, {r3-r9} - b MEM_LongCopyEnd - ldmia.w r1!, {r3-r10} @ 32 bytes remain - stmia.w r0!, {r3-r10} - b MEM_LongCopyEnd - ldmia.w r1!, {r3-r11} @ 36 bytes remain - stmia.w r0!, {r3-r11} - -MEM_LongCopyEnd: - pop {r4-r12} - and r2, r2, #0x03 @ All the longs have been copied - -@ ---------------------------------------------------------------------------- - -MEM_DataCopyBytes: - @ Deal with up to 3 remaining bytes - cmp r2, #0x00 - it eq - popeq {pc} - ldrb r3, [r1], #0x01 - strb r3, [r0], #0x01 - subs r2, r2, #0x01 - it eq - popeq {pc} - ldrb r3, [r1], #0x01 - strb r3, [r0], #0x01 - subs r2, r2, #0x01 - it eq - popeq {pc} - ldrb r3, [r1], #0x01 - strb r3, [r0], #0x01 - pop {pc} - - .align 4 - -@ ---------------------------------------------------------------------------- -@ Bits: Src=01, Dst=11 - Byte before half word to byte before long word -@ 3 bytes to read for long word aligning the source - -MEM_DataCopy7: - ldrb r3, [r1], #0x01 - strb r3, [r0], #0x01 - sub r2, r2, #0x01 - -@ ---------------------------------------------------------------------------- -@ Bits: Src=10, Dst=00 - Half word to long word -@ 2 bytes to read for long word aligning the source - -MEM_DataCopy8: - ldrb r3, [r1], #0x01 - strb r3, [r0], #0x01 - sub r2, r2, #0x01 - -@ ---------------------------------------------------------------------------- -@ Bits: Src=11, Dst=01 - Byte before long word to byte before half word -@ 1 byte to read for long word aligning the source - -MEM_DataCopy13: - ldrb r3, [r1], #0x01 - strb r3, [r0], #0x01 - sub r2, r2, #0x01 - -@ ---------------------------------------------------------------------------- -@ Bits: Src=00, Dst=10 - Long to Half word - -MEM_DataCopy2: - cmp r2, #0x28 - blt MEM_DataCopy2_1 - - @ Save regs - push {r4-r12} -MEM_DataCopy2_2: - ldmia r1!, {r3-r12} - - strh r3, [r0], #0x02 - - lsr r3, r3, #0x10 - bfi r3, r4, #0x10, #0x10 - lsr r4, r4, #0x10 - bfi r4, r5, #0x10, #0x10 - lsr r5, r5, #0x10 - bfi r5, r6, #0x10, #0x10 - lsr r6, r6, #0x10 - bfi r6, r7, #0x10, #0x10 - lsr r7, r7, #0x10 - bfi r7, r8, #0x10, #0x10 - lsr r8, r8, #0x10 - bfi r8, r9, #0x10, #0x10 - lsr r9, r9, #0x10 - bfi r9, r10, #0x10, #0x10 - lsr r10, r10, #0x10 - bfi r10, r11, #0x10, #0x10 - lsr r11, r11, #0x10 - bfi r11, r12, #0x10, #0x10 - stmia r0!, {r3-r11} - lsr r12, r12, #0x10 - strh r12, [r0], #0x02 - - sub r2, r2, #0x28 - cmp r2, #0x28 - bge MEM_DataCopy2_2 - pop {r4-r12} - -MEM_DataCopy2_1: @ Read longs and write 2 x half words - cmp r2, #4 - blt MEM_DataCopyBytes - ldr r3, [r1], #0x04 - strh r3, [r0], #0x02 - lsr r3, r3, #0x10 - strh r3, [r0], #0x02 - sub r2, r2, #0x04 - b MEM_DataCopy2 - -@ ---------------------------------------------------------------------------- -@ Bits: Src=01, Dst=00 - Byte before half word to long -@ Bits: Src=01, Dst=10 - Byte before half word to half word -@ 3 bytes to read for long word aligning the source - -MEM_DataCopy4: -MEM_DataCopy6: - @ Read B and write B - ldrb r3, [r1], #0x01 - strb r3, [r0], #0x01 - sub r2, r2, #0x01 - -@ ---------------------------------------------------------------------------- -@ Bits: Src=10, Dst=01 - Half word to byte before half word -@ Bits: Src=10, Dst=11 - Half word to byte before long word -@ 2 bytes to read for long word aligning the source - -MEM_DataCopy9: -MEM_DataCopy11: - ldrb r3, [r1], #0x01 - strb r3, [r0], #0x01 - sub r2, r2, #0x01 - -@ ---------------------------------------------------------------------------- -@ Bits: Src=11, Dst=00 - Byte before long word to long word -@ Bits: Src=11, Dst=11 - Byte before long word to half word -@ 1 byte to read for long word aligning the source - -MEM_DataCopy12: -MEM_DataCopy14: - @ Read B and write B - ldrb r3, [r1], #0x01 - strb r3, [r0], #0x01 - sub r2, r2, #0x01 - -@ ---------------------------------------------------------------------------- -@ Bits: Src=00, Dst=01 - Long to Byte before half word -@ Bits: Src=00, Dst=11 - Long to Byte before long word - -MEM_DataCopy1: @ Read longs, write B->H->B -MEM_DataCopy3: - cmp r2, #4 - blt MEM_DataCopyBytes - ldr r3, [r1], #0x04 - strb r3, [r0], #0x01 - lsr r3, r3, #0x08 - strh r3, [r0], #0x02 - lsr r3, r3, #0x10 - strb r3, [r0], #0x01 - sub r2, r2, #0x04 - b MEM_DataCopy3 - -@ ---------------------------------------------------------------------------- - |