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checkpoint: atom 0-1 works for resolve look at.

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ed
2026-08-11 14:05:23 -04:00
parent 3f3b691ac0
commit 7daeec0ee3
5 changed files with 20 additions and 18 deletions
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code/duffle/gte.atom.c
+11 -6
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@@ -225,20 +225,22 @@ MipsAtom_Proc_(normalize_v3s4, aa, {
/* Stage 3: compute srav amount (r_lzcr) + align |v|² to bit 24.
* IMPORTANT: the sllv/srav below writes the aligned |v|² to r_mac1_scratch (NOT r_lzcr),
* so r_lzcr retains the shift count all the way to the start of stage 4. */
* so r_lzcr retains the shift count all the way to the start of stage 4.
*/
and_i( r_shift, r_shift, -2),
or_u(r_mac1_scratch, r_lzcr, 0), /* FIX B: save sum before clobbering r_lzcr with shift count */
li_s( r_lzcr, 31),
sub_s( r_lzcr, r_lzcr, r_shift),
shift_aright(r_lzcr, r_lzcr, 1),
/* r_branch_tmp = LZCR - 24 (overwrites r_branch_tmp; src.z no longer needed after SQR) */
add_si( r_branch_tmp, r_shift, -24),
branch_lt_zero(r_branch_tmp, atom_offset(srav_path, aligned_done)), nop,
jump_rel(atom_offset(aligned_done, srav_path)),
shift_lleft_var(r_mac1_scratch, r_lzcr, r_branch_tmp), /* sllv path: aligned = r_lzcr sll (LZCR-24) — dst=r_mac1_scratch to PRESERVE r_lzcr=shift count */
branch_lt_zero(r_branch_tmp, atom_offset(aligned_done, srav_path)), nop, /* FIX A: bltz → srav_path (LZCR<24 path) */
jump_rel(atom_offset(srav_path, aligned_done)), /* FIX A: b → aligned_done (LZCR>=24 path) */
shift_lleft_var(r_mac1_scratch, r_mac1_scratch, r_branch_tmp), /* FIX B: src=sum (r_mac1_scratch), dst=same */
atom_label(srav_path)
li_s( r_branch_tmp, 24),
sub_s( r_branch_tmp, r_branch_tmp, r_shift),
shift_aright_var(r_mac1_scratch, r_lzcr, r_branch_tmp), /* srav path: aligned = r_lzcr sra (24-LZCR) — dst=r_mac1_scratch to PRESERVE r_lzcr=shift count */
shift_aright_var(r_mac1_scratch, r_mac1_scratch, r_branch_tmp), /* FIX B: src=sum (r_mac1_scratch), dst=same */
atom_label(aligned_done)
/* Save the shift count to r_shift before the next 5 instructions overwrite r_lzcr
* (the sqrtbl lookup loads 1/|v| into r_lzcr, which becomes IR0 in stage 4). */
@@ -251,11 +253,14 @@ MipsAtom_Proc_(normalize_v3s4, aa, {
add_u(r_branch_tmp, r_branch_tmp, r_mac1_scratch),
load_half(r_lzcr, r_branch_tmp, 0), nop, /* r_lzcr = sqrtbl[aligned-64] = 1/|v| (IR0 in stage 4) */
/* FIX bug C: r_branch_tmp held the sqrtbl base+index, NOT src.z. Reload src.z from scratch now that r_branch_tmp is free. */
load_word(r_branch_tmp, r_src_ptr, O_(V3_S4,z)), nop, /* r_branch_tmp = src.z (for IR3 in stage 4) */
/* Stage 4: GPF + srav finalize (r_shift = shift count, r_lzcr = 1/|v|). */
gte_mv_to_data_r(r_lzcr, C2_IR0),
gte_mv_to_data_r(r_tmp, C2_IR1), /* IR1 = src.x (preserved in r_tmp — r_mac2_scratch was clobbered to MAC2 in stage 1.5) */
gte_mv_to_data_r(r_recip_est, C2_IR2),
gte_mv_to_data_r(r_branch_tmp, C2_IR3),
gte_mv_to_data_r(r_branch_tmp, C2_IR3), /* IR3 = src.z (reloaded) */
nop2, gte_cmdw_gpf,
gte_mv_from_data_r(r_mac2_scratch, C2_MAC1),
gte_mv_from_data_r(r_recip_est, C2_MAC2),