So we don't need to reuse a register and rematerialize a constant. I couldn't count :(. Signed-off-by: Xi Ruoyao <xry111@xxxxxxxxxxx> --- Tested with vdso_test_getrandom and vdso_test_chacha. arch/loongarch/vdso/vgetrandom-chacha.S | 13 +++---------- 1 file changed, 3 insertions(+), 10 deletions(-) diff --git a/arch/loongarch/vdso/vgetrandom-chacha.S b/arch/loongarch/vdso/vgetrandom-chacha.S index c2733e6c3a8d..c4dd2bab8825 100644 --- a/arch/loongarch/vdso/vgetrandom-chacha.S +++ b/arch/loongarch/vdso/vgetrandom-chacha.S @@ -58,9 +58,7 @@ SYM_FUNC_START(__arch_chacha20_blocks_nostack) #define copy0 t5 #define copy1 t6 #define copy2 t7 - -/* Reuse i as copy3 */ -#define copy3 i +#define copy3 t8 /* Packs to be used with OP_4REG */ #define line0 state0, state1, state2, state3 @@ -99,6 +97,7 @@ SYM_FUNC_START(__arch_chacha20_blocks_nostack) li.w copy0, 0x61707865 li.w copy1, 0x3320646e li.w copy2, 0x79622d32 + li.w copy3, 0x6b206574 ld.w cnt_lo, counter, 0 ld.w cnt_hi, counter, 4 @@ -108,7 +107,7 @@ SYM_FUNC_START(__arch_chacha20_blocks_nostack) move state0, copy0 move state1, copy1 move state2, copy2 - li.w state3, 0x6b206574 + move state3, copy3 /* state[4,5,..,11] = key */ ld.w state4, key, 0 @@ -167,12 +166,6 @@ SYM_FUNC_START(__arch_chacha20_blocks_nostack) addi.w i, i, -1 bnez i, .Lpermute - /* - * copy[3] = "expa", materialize it here because copy[3] shares the - * same register with i which just became dead. - */ - li.w copy3, 0x6b206574 - /* output[0,1,2,3] = copy[0,1,2,3] + state[0,1,2,3] */ OP_4REG add.w line0, copy st.w state0, output, 0 -- 2.48.1
