diff options
| author | Usama Arif <usama.arif@arm.com> | 2018-12-12 17:08:33 +0000 |
|---|---|---|
| committer | Usama Arif <usama.arif@arm.com> | 2019-02-19 17:07:48 +0000 |
| commit | a5aa25af6514ff04721efce05e46b4daf8729a85 (patch) | |
| tree | edfa3429fd232129a838c6043c84928ddff63c60 /include/arch | |
| parent | c9fe6fed4bcd930af4ccc487633b35e92d3cc288 (diff) | |
Division functionality for cores that dont have divide hardware.
Cortex a5 doesnt support hardware division such as sdiv and udiv commands.
This commit adds a software division function in assembly as well as include
appropriate files for software divison.
The software division algorithm is a modified version obtained from:
http://www.keil.com/support/man/docs/armasm/armasm_dom1359731155623.htm
Change-Id: Ib405a330da5f1cea1e68e07e7b520edeef9e2652
Signed-off-by: Usama Arif <usama.arif@arm.com>
Diffstat (limited to 'include/arch')
| -rw-r--r-- | include/arch/aarch32/asm_macros.S | 29 |
1 files changed, 28 insertions, 1 deletions
diff --git a/include/arch/aarch32/asm_macros.S b/include/arch/aarch32/asm_macros.S index 8408804f..8cfa2123 100644 --- a/include/arch/aarch32/asm_macros.S +++ b/include/arch/aarch32/asm_macros.S @@ -78,7 +78,7 @@ * Clobber: r14, r1, r2 */ .macro get_my_mp_stack _name, _size - bl plat_my_core_pos + bl plat_my_core_pos ldr r2, =(\_name + \_size) mov r1, #\_size mla r0, r0, r1, r2 @@ -189,4 +189,31 @@ .endif .endm + /* + * Helper macro for carrying out division in software when + * hardware division is not suported. \top holds the dividend + * in the function call and the remainder after + * the function is executed. \bot holds the divisor. \div holds + * the quotient and \temp is a temporary registed used in calcualtion. + * The division algorithm has been obtained from: + * http://www.keil.com/support/man/docs/armasm/armasm_dom1359731155623.htm + */ + .macro softudiv div:req,top:req,bot:req,temp:req + + mov \temp, \bot + cmp \temp, \top, lsr #1 +div1: + movls \temp, \temp, lsl #1 + cmp \temp, \top, lsr #1 + bls div1 + mov \div, #0 + +div2: + cmp \top, \temp + subcs \top, \top,\temp + ADC \div, \div, \div + mov \temp, \temp, lsr #1 + cmp \temp, \bot + bhs div2 + .endm #endif /* ASM_MACROS_S */ |