diff options
Diffstat (limited to 'runtime/powerpc/i64_stof.s')
| -rw-r--r-- | runtime/powerpc/i64_stof.s | 17 |
1 files changed, 8 insertions, 9 deletions
diff --git a/runtime/powerpc/i64_stof.s b/runtime/powerpc/i64_stof.s index 97fa6bb8..ea23a1c8 100644 --- a/runtime/powerpc/i64_stof.s +++ b/runtime/powerpc/i64_stof.s @@ -43,20 +43,19 @@ __compcert_i64_stof: mflr r9 # Check whether -2^53 <= X < 2^53 - srawi r5, r3, 31 - srawi r6, r3, 21 # (r5,r6) = X >> 53 - addic r6, r6, 1 - addze r5, r5 # (r5,r6) = (X >> 53) + 1 + srawi r5, r3, 21 # r5 = high 32 bits of X >> 53 + # -2^53 <= X < 2^53 iff r5 is -1 or 0, that is, iff r5 + 1 is 0 or 1 + addi r5, r5, 1 cmplwi r5, 2 blt 1f # X is large enough that double rounding can occur. # Avoid it by nudging X away from the points where double rounding # occurs (the "round to odd" technique) - rlwinm r0, r4, 0, 21, 31 # extract bits 0 to 11 of X - addi r0, r0, 0x7FF # r0 = (X & 0x7FF) + 0x7FF - # bit 12 of r0 is 0 if all low 12 bits of X are 0, 1 otherwise - # bits 13-31 of r0 are 0 - or r4, r4, r0 # correct bit number 12 of X + rlwinm r5, r4, 0, 21, 31 # extract bits 0 to 11 of X + addi r5, r5, 0x7FF # r5 = (X & 0x7FF) + 0x7FF + # bit 12 of r5 is 0 if all low 12 bits of X are 0, 1 otherwise + # bits 13-31 of r5 are 0 + or r4, r4, r5 # correct bit number 12 of X rlwinm r4, r4, 0, 0, 20 # set to 0 bits 0 to 11 of X # Convert to double, then round to single 1: bl __compcert_i64_stod |