From 14c23438b4cf1b65e1885f9e6898b8f06e972cb7 Mon Sep 17 00:00:00 2001 From: cecilarmitais Date: Wed, 22 Jul 2026 02:33:28 -0700 Subject: [PATCH] Decomp UFixedPoint64CmpLt Decompile UFixedPoint64CmpLt (0x02001A30) from asm. It compares two 64-bit values held as high/low word pairs and returns whether the first is less than the second. asm/main_02001A30.s held only this function, so the file and its .inc are removed rather than split, the function merges into the adjacent src/main_020018D0.c, and main.lsf drops asm/main_02001A30.o. Three details of the interface are read off the target rather than assumed, each tested with the others held fixed. The four words arrive as separate parameters: a 2-word struct passed by value makes the compiler push all four argument registers and reload them, which the target does not do. Those parameters are unsigned: the comparisons select movlo/movhi, where signed high words give movlt/movgt. The return is word-sized: a u8-width return such as bool8 appends and r0, r0, #0xff, which the target does not have. BOOL is used rather than int because it is the tree's word-sized boolean, and it produces the same bytes. src/main_02001BB4.c declared this function from its call site, before it was decompiled. That declaration is replaced by an include of the header. It was never visible to the compiler at the same time as the definition, so the two disagreeing prototypes could not be caught by a build; its parameter types were signed, which does not describe this function. No comments are added to any pmd-sky file. Authored by Claude (Opus 4.8, amended by Opus 5) under human direction. Confirmed by a matching build: build/pmdsky.us/pmdsky.us.nds: OK. Co-Authored-By: Claude Opus 4.8 Co-Authored-By: Claude Opus 5 --- asm/include/main_02001A30.inc | 2 -- asm/main_02001A30.s | 18 ------------------ include/main_020018D0.h | 1 + main.lsf | 1 - src/main_020018D0.c | 11 +++++++++++ src/main_02001BB4.c | 3 +-- 6 files changed, 13 insertions(+), 23 deletions(-) delete mode 100644 asm/include/main_02001A30.inc delete mode 100644 asm/main_02001A30.s diff --git a/asm/include/main_02001A30.inc b/asm/include/main_02001A30.inc deleted file mode 100644 index 3f59c932..00000000 --- a/asm/include/main_02001A30.inc +++ /dev/null @@ -1,2 +0,0 @@ -#pragma once - diff --git a/asm/main_02001A30.s b/asm/main_02001A30.s deleted file mode 100644 index f2d576cd..00000000 --- a/asm/main_02001A30.s +++ /dev/null @@ -1,18 +0,0 @@ - .include "asm/macros.inc" - .include "main_02001A30.inc" - - .text - -; https://decomp.me/scratch/bOtSO - arm_func_start UFixedPoint64CmpLt -UFixedPoint64CmpLt: ; 0x02001A30 - cmp r0, r2 - movlo r0, #1 - bxlo lr - movhi r0, #0 - bxhi lr - cmp r1, r3 - movlo r0, #1 - movhs r0, #0 - bx lr - arm_func_end UFixedPoint64CmpLt diff --git a/include/main_020018D0.h b/include/main_020018D0.h index 253ac59a..7cf5cb6f 100644 --- a/include/main_020018D0.h +++ b/include/main_020018D0.h @@ -3,5 +3,6 @@ s32 SinAbs4096(s32 x); s32 CosAbs4096(s32 x); +BOOL UFixedPoint64CmpLt(u32 a_hi, u32 a_lo, u32 b_hi, u32 b_lo); #endif //PMDSKY_MAIN_020018D0_H diff --git a/main.lsf b/main.lsf index 6de52d4a..c9019054 100644 --- a/main.lsf +++ b/main.lsf @@ -17,7 +17,6 @@ Static main Object src/main_02001894.o Object asm/main_020018A4.o Object src/main_020018D0.o - Object asm/main_02001A30.o Object src/main_02001A54.o Object asm/main_02001B0C.o Object src/main_02001BB4.o diff --git a/src/main_020018D0.c b/src/main_020018D0.c index 8b37bc75..8f90c44c 100644 --- a/src/main_020018D0.c +++ b/src/main_020018D0.c @@ -36,3 +36,14 @@ s32 CosAbs4096(s32 x) return 0; } } + +BOOL UFixedPoint64CmpLt(u32 a_hi, u32 a_lo, u32 b_hi, u32 b_lo) +{ + if (a_hi < b_hi) { + return TRUE; + } + if (a_hi > b_hi) { + return FALSE; + } + return a_lo < b_lo; +} diff --git a/src/main_02001BB4.c b/src/main_02001BB4.c index 8032a27b..f5d3a288 100644 --- a/src/main_02001BB4.c +++ b/src/main_02001BB4.c @@ -1,7 +1,6 @@ +#include "main_020018D0.h" #include "main_02001BB4.h" -extern s32 UFixedPoint64CmpLt(s32, u32, s32, u32); - u32 sub_02001BB4(s32 x, s32 y) { u32 var_r4;