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| author | Michael Brown <mcb30@ipxe.org> | 2016-05-08 00:18:35 +0100 |
|---|---|---|
| committer | Michael Brown <mcb30@ipxe.org> | 2016-05-08 00:18:35 +0100 |
| commit | edea3a434ccae8dc980c715949287c9ba63babf5 (patch) | |
| tree | d821d987dcf1ac0bc4f22e1363fa32c95f6bd0b2 /src/arch/arm32/libgcc/llshift.S | |
| parent | 2a187f480ecc9d7943a53658e748bb5e60104788 (diff) | |
| download | ipxe-edea3a434ccae8dc980c715949287c9ba63babf5.tar.gz | |
[arm] Split out 32-bit-specific code to arch/arm32
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Diffstat (limited to 'src/arch/arm32/libgcc/llshift.S')
| -rw-r--r-- | src/arch/arm32/libgcc/llshift.S | 88 |
1 files changed, 88 insertions, 0 deletions
diff --git a/src/arch/arm32/libgcc/llshift.S b/src/arch/arm32/libgcc/llshift.S new file mode 100644 index 000000000..cc16e2615 --- /dev/null +++ b/src/arch/arm32/libgcc/llshift.S @@ -0,0 +1,88 @@ +FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL ) + + .text + .arm + +/** + * Logical shift left + * + * @v r1:r0 Value to shift + * @v r2 Shift amount + * @ret r1:r0 Shifted value + */ + .section ".text.__aeabi_llsl", "ax", %progbits + .globl __aeabi_llsl + .type __aeabi_llsl, %function +__aeabi_llsl: + /* r3 = ( shift - 32 ) */ + subs r3, r2, #32 + /* If shift >= 32, then + * high = ( low << ( shift - 32 ) ) + */ + movpl r1, r0, lsl r3 + /* If shift < 32, then + * high = ( ( high << shift ) | ( low >> ( 32 - shift ) ) ) + */ + movmi r1, r1, lsl r2 + rsbmi r3, r2, #32 + orrmi r1, r1, r0, lsr r3 + /* low = ( low << shift ) */ + mov r0, r0, lsl r2 + bx lr + .size __aeabi_llsl, . - __aeabi_llsl + +/** + * Logical shift right + * + * @v r1:r0 Value to shift + * @v r2 Shift amount + * @ret r1:r0 Shifted value + */ + .section ".text.__aeabi_llsr", "ax", %progbits + .globl __aeabi_llsr + .type __aeabi_llsr, %function +__aeabi_llsr: + /* r3 = ( shift - 32 ) */ + subs r3, r2, #32 + /* If shift >= 32, then + * low = ( high >> ( shift - 32 ) ) + */ + movpl r0, r1, lsr r3 + /* If shift < 32, then + * low = ( ( low >> shift ) | ( high << ( 32 - shift ) ) ) + */ + movmi r0, r0, lsr r2 + rsbmi r3, r2, #32 + orrmi r0, r0, r1, lsl r3 + /* high = ( high >> shift ) */ + mov r1, r1, lsr r2 + bx lr + .size __aeabi_llsr, . - __aeabi_llsr + +/** + * Arithmetic shift right + * + * @v r1:r0 Value to shift + * @v r2 Shift amount + * @ret r1:r0 Shifted value + */ + .section ".text.__aeabi_lasr", "ax", %progbits + .globl __aeabi_lasr + .type __aeabi_lasr, %function +__aeabi_lasr: + /* r3 = ( shift - 32 ) */ + subs r3, r2, #32 + /* If shift >= 32, then + * low = ( high >> ( shift - 32 ) ) + */ + movpl r0, r1, asr r3 + /* If shift < 32, then + * low = ( ( low >> shift ) | ( high << ( 32 - shift ) ) ) + */ + movmi r0, r0, lsr r2 + rsbmi r3, r2, #32 + orrmi r0, r0, r1, lsl r3 + /* high = ( high >> shift ) */ + mov r1, r1, asr r2 + bx lr + .size __aeabi_lasr, . - __aeabi_lasr |