Replace ASM signed tests with unsigned

ge, lt, gt and le condition codes in assembly provide a signed test
whereas hs, lo, hi and ls provide the unsigned counterpart. Signed tests
should only be used when strictly necessary, as using them on logically
unsigned values can lead to inverting the test for high enough values.
All offsets, addresses and usually counters are actually unsigned
values, and should be tested as such.

Replace the occurrences of signed condition codes where it was
unnecessary by an unsigned test as the unsigned tests allow the full
range of unsigned values to be used without inverting the result with
some large operands.

Change-Id: I58b7e98d03e3a4476dfb45230311f296d224980a
Signed-off-by: Douglas Raillard <douglas.raillard@arm.com>
This commit is contained in:
Douglas Raillard 2017-03-07 16:36:14 +00:00
parent fa971fca2f
commit 355a5d0336
4 changed files with 10 additions and 10 deletions

View File

@ -118,7 +118,7 @@ loop1:
mov r12, r2, LSR r10 // extract cache type bits from clidr
and r12, r12, #7 // mask the bits for current cache only
cmp r12, #2 // see what cache we have at this level
blt level_done // no cache or only instruction cache at this level
blo level_done // no cache or only instruction cache at this level
stcopr r1, CSSELR // select current cache level in csselr
isb // isb to sych the new cssr&csidr
@ -138,14 +138,14 @@ loop3:
blx r6
subs r7, r7, #1 // decrement the set number
bge loop3
bhs loop3
subs r9, r9, #1 // decrement the way number
bge loop2
bhs loop2
level_done:
add r1, r1, #2 // increment the cache number
cmp r3, r1
dsb sy // ensure completion of previous cache maintenance instruction
bgt loop1
bhi loop1
mov r6, #0
stcopr r6, CSSELR //select cache level 0 in csselr

View File

@ -170,7 +170,7 @@ func memcpy4
/* copy 4 bytes at a time */
m_loop4:
cmp r2, #4
blt m_loop1
blo m_loop1
ldr r3, [r1], #4
str r3, [r0], #4
sub r2, r2, #4

View File

@ -119,7 +119,7 @@ loop1:
lsr x1, x0, x2 // extract cache type bits from clidr
and x1, x1, #7 // mask the bits for current cache only
cmp x1, #2 // see what cache we have at this level
b.lt level_done // nothing to do if no cache or icache
b.lo level_done // nothing to do if no cache or icache
msr csselr_el1, x10 // select current cache level in csselr
isb // isb to sych the new cssr&csidr
@ -144,10 +144,10 @@ loop3_\_op:
orr w11, w9, w7 // combine cache, way and set number
dc \_op, x11
subs w7, w7, w17 // decrement set number
b.ge loop3_\_op
b.hs loop3_\_op
subs x9, x9, x16 // decrement way number
b.ge loop2_\_op
b.hs loop2_\_op
b level_done
.endm
@ -155,7 +155,7 @@ loop3_\_op:
level_done:
add x10, x10, #2 // increment cache number
cmp x3, x10
b.gt loop1
b.hi loop1
msr csselr_el1, xzr // select cache level 0 in csselr
dsb sy // barrier to complete final cache operation
isb

View File

@ -157,7 +157,7 @@ func get_cpu_ops_ptr
1:
/* Check if we have reached end of list */
cmp r4, r5
bge error_exit
bhs error_exit
/* load the midr from the cpu_ops */
ldr r1, [r4], #CPU_OPS_SIZE