This will bring at most 50% performance gain on loongson3a. See http://dev.lemote.com/files/upload/software/csum-opti/csum-opti-benchmark.html The benchmark is done in userspace through http://dev.lemote.com/files/upload/software/csum-opti/csum-test.tar.gz --- arch/mips/lib/csum_partial.S | 38 +++++++++++++++++++------------------- 1 file changed, 19 insertions(+), 19 deletions(-) diff --git a/arch/mips/lib/csum_partial.S b/arch/mips/lib/csum_partial.S index 9901237..6cea101 100644 --- a/arch/mips/lib/csum_partial.S +++ b/arch/mips/lib/csum_partial.S @@ -76,10 +76,10 @@ LOAD _t1, (offset + UNIT(1))(src); \ LOAD _t2, (offset + UNIT(2))(src); \ LOAD _t3, (offset + UNIT(3))(src); \ + ADDC(_t0, _t1); \ + ADDC(_t2, _t3); \ ADDC(sum, _t0); \ - ADDC(sum, _t1); \ - ADDC(sum, _t2); \ - ADDC(sum, _t3) + ADDC(sum, _t2) #ifdef USE_DOUBLE #define CSUM_BIGCHUNK(src, offset, sum, _t0, _t1, _t2, _t3) \ @@ -501,21 +501,21 @@ LEAF(csum_partial) SUB len, len, 8*NBYTES ADD src, src, 8*NBYTES STORE(t0, UNIT(0)(dst), .Ls_exc\@) - ADDC(sum, t0) + ADDC(t0, t1) STORE(t1, UNIT(1)(dst), .Ls_exc\@) - ADDC(sum, t1) + ADDC(sum, t0) STORE(t2, UNIT(2)(dst), .Ls_exc\@) - ADDC(sum, t2) + ADDC(t2, t3) STORE(t3, UNIT(3)(dst), .Ls_exc\@) - ADDC(sum, t3) + ADDC(sum, t2) STORE(t4, UNIT(4)(dst), .Ls_exc\@) - ADDC(sum, t4) + ADDC(t4, t5) STORE(t5, UNIT(5)(dst), .Ls_exc\@) - ADDC(sum, t5) + ADDC(sum, t4) STORE(t6, UNIT(6)(dst), .Ls_exc\@) - ADDC(sum, t6) + ADDC(t6, t7) STORE(t7, UNIT(7)(dst), .Ls_exc\@) - ADDC(sum, t7) + ADDC(sum, t6) .set reorder /* DADDI_WAR */ ADD dst, dst, 8*NBYTES bgez len, 1b @@ -541,13 +541,13 @@ LEAF(csum_partial) SUB len, len, 4*NBYTES ADD src, src, 4*NBYTES STORE(t0, UNIT(0)(dst), .Ls_exc\@) - ADDC(sum, t0) + ADDC(t0, t1) STORE(t1, UNIT(1)(dst), .Ls_exc\@) - ADDC(sum, t1) + ADDC(sum, t0) STORE(t2, UNIT(2)(dst), .Ls_exc\@) - ADDC(sum, t2) + ADDC(t2, t3) STORE(t3, UNIT(3)(dst), .Ls_exc\@) - ADDC(sum, t3) + ADDC(sum, t2) .set reorder /* DADDI_WAR */ ADD dst, dst, 4*NBYTES beqz len, .Ldone\@ @@ -646,13 +646,13 @@ LEAF(csum_partial) nop # improves slotting #endif STORE(t0, UNIT(0)(dst), .Ls_exc\@) - ADDC(sum, t0) + ADDC(t0, t1) STORE(t1, UNIT(1)(dst), .Ls_exc\@) - ADDC(sum, t1) + ADDC(sum, t0) STORE(t2, UNIT(2)(dst), .Ls_exc\@) - ADDC(sum, t2) + ADDC(t2, t3) STORE(t3, UNIT(3)(dst), .Ls_exc\@) - ADDC(sum, t3) + ADDC(sum, t2) .set reorder /* DADDI_WAR */ ADD dst, dst, 4*NBYTES bne len, rem, 1b -- 1.9.0
