1 files changed, 44 insertions, 41 deletions

diff --git a/arch/arm/lib/memset.S b/arch/arm/lib/memset.S
index 650d5923ab83..d912e7397ecc 100644
--- a/arch/arm/lib/memset.S
+++ b/arch/arm/lib/memset.S
@@ -19,9 +19,9 @@
 1:      subs    r2, r2, #4              @ 1 do we have enough
         blt     5f                      @ 1 bytes to align with?
         cmp     r3, #2                  @ 1
-        strltb  r1, [r0], #1            @ 1
-        strleb  r1, [r0], #1            @ 1
-        strb    r1, [r0], #1            @ 1
+        strltb  r1, [ip], #1            @ 1
+        strleb  r1, [ip], #1            @ 1
+        strb    r1, [ip], #1            @ 1
         add     r2, r2, r3              @ 1 (r2 = r2 - (4 - r3))
 /*
  * The pointer is now aligned and the length is adjusted.  Try doing the
@@ -29,10 +29,14 @@
  */
 
 ENTRY(memset)
-        ands    r3, r0, #3              @ 1 unaligned?
+/*
+ * Preserve the contents of r0 for the return value.
+ */
+        mov     ip, r0
+        ands    r3, ip, #3              @ 1 unaligned?
         bne     1b                      @ 1
 /*
- * we know that the pointer in r0 is aligned to a word boundary.
+ * we know that the pointer in ip is aligned to a word boundary.
  */
         orr     r1, r1, r1, lsl #8
         orr     r1, r1, r1, lsl #16
@@ -43,29 +47,28 @@ ENTRY(memset)
 #if ! CALGN(1)+0
 
 /*
- * We need an extra register for this loop - save the return address and
- * use the LR
+ * We need 2 extra registers for this loop - use r8 and the LR
  */
-        str     lr, [sp, #-4]!
-        mov     ip, r1
+        stmfd   sp!, {r8, lr}
+        mov     r8, r1
         mov     lr, r1
 
 2:      subs    r2, r2, #64
-        stmgeia r0!, {r1, r3, ip, lr}   @ 64 bytes at a time.
-        stmgeia r0!, {r1, r3, ip, lr}
-        stmgeia r0!, {r1, r3, ip, lr}
-        stmgeia r0!, {r1, r3, ip, lr}
+        stmgeia ip!, {r1, r3, r8, lr}   @ 64 bytes at a time.
+        stmgeia ip!, {r1, r3, r8, lr}
+        stmgeia ip!, {r1, r3, r8, lr}
+        stmgeia ip!, {r1, r3, r8, lr}
         bgt     2b
-        ldmeqfd sp!, {pc}               @ Now <64 bytes to go.
+        ldmeqfd sp!, {r8, pc}           @ Now <64 bytes to go.
 /*
  * No need to correct the count; we're only testing bits from now on
  */
         tst     r2, #32
-        stmneia r0!, {r1, r3, ip, lr}
-        stmneia r0!, {r1, r3, ip, lr}
+        stmneia ip!, {r1, r3, r8, lr}
+        stmneia ip!, {r1, r3, r8, lr}
         tst     r2, #16
-        stmneia r0!, {r1, r3, ip, lr}
-        ldr     lr, [sp], #4
+        stmneia ip!, {r1, r3, r8, lr}
+        ldmfd   sp!, {r8, lr}
 
 #else
 
@@ -74,54 +77,54 @@ ENTRY(memset)
  * whole cache lines at once.
  */
 
-        stmfd   sp!, {r4-r7, lr}
+        stmfd   sp!, {r4-r8, lr}
         mov     r4, r1
         mov     r5, r1
         mov     r6, r1
         mov     r7, r1
-        mov     ip, r1
+        mov     r8, r1
         mov     lr, r1
 
         cmp     r2, #96
-        tstgt   r0, #31
+        tstgt   ip, #31
         ble     3f
 
-        and     ip, r0, #31
-        rsb     ip, ip, #32
-        sub     r2, r2, ip
-        movs    ip, ip, lsl #(32 - 4)
-        stmcsia r0!, {r4, r5, r6, r7}
-        stmmiia r0!, {r4, r5}
-        tst     ip, #(1 << 30)
-        mov     ip, r1
-        strne   r1, [r0], #4
+        and     r8, ip, #31
+        rsb     r8, r8, #32
+        sub     r2, r2, r8
+        movs    r8, r8, lsl #(32 - 4)
+        stmcsia ip!, {r4, r5, r6, r7}
+        stmmiia ip!, {r4, r5}
+        tst     r8, #(1 << 30)
+        mov     r8, r1
+        strne   r1, [ip], #4
 
 3:      subs    r2, r2, #64
-        stmgeia r0!, {r1, r3-r7, ip, lr}
-        stmgeia r0!, {r1, r3-r7, ip, lr}
+        stmgeia ip!, {r1, r3-r8, lr}
+        stmgeia ip!, {r1, r3-r8, lr}
         bgt     3b
-        ldmeqfd sp!, {r4-r7, pc}
+        ldmeqfd sp!, {r4-r8, pc}
 
         tst     r2, #32
-        stmneia r0!, {r1, r3-r7, ip, lr}
+        stmneia ip!, {r1, r3-r8, lr}
         tst     r2, #16
-        stmneia r0!, {r4-r7}
-        ldmfd   sp!, {r4-r7, lr}
+        stmneia ip!, {r4-r7}
+        ldmfd   sp!, {r4-r8, lr}
 
 #endif
 
 4:      tst     r2, #8
-        stmneia r0!, {r1, r3}
+        stmneia ip!, {r1, r3}
         tst     r2, #4
-        strne   r1, [r0], #4
+        strne   r1, [ip], #4
 /*
  * When we get here, we've got less than 4 bytes to zero.  We
  * may have an unaligned pointer as well.
  */
 5:      tst     r2, #2
-        strneb  r1, [r0], #1
-        strneb  r1, [r0], #1
+        strneb  r1, [ip], #1
+        strneb  r1, [ip], #1
         tst     r2, #1
-        strneb  r1, [r0], #1
+        strneb  r1, [ip], #1
         mov     pc, lr
 ENDPROC(memset)