Fix signed overflow calculation in ADCS/SBCS when using overflow buil…

…tins
CE-Programming · Aug 19, 2024 · ad69900 · ad69900
1 parent d74e293
commit ad69900
Showing 1 changed file with 2 additions and 2 deletions.
diff --git a/core/arm/armcpu.c b/core/arm/armcpu.c
@@ -317,7 +317,7 @@ static uint32_t arm_adcs(arm_cpu_t *cpu, uint32_t x, uint32_t y) {
     bool carry = cpu->c;
     int32_t res;
     cpu->v = __builtin_add_overflow(x, y, &res);
-    cpu->v |= __builtin_add_overflow(res, carry, &res);
+    cpu->v ^= __builtin_add_overflow(res, carry, &res);
     cpu->c = __builtin_add_overflow(x, y, &x);
     cpu->c |= __builtin_add_overflow(x, carry, &x);
     return arm_movs(cpu, x);
@@ -347,7 +347,7 @@ static uint32_t arm_sbcs(arm_cpu_t *cpu, uint32_t x, uint32_t y) {
     bool borrow = !cpu->c;
     int32_t res;
     cpu->v = __builtin_sub_overflow(x, y, &res);
-    cpu->v |= __builtin_sub_overflow(res, borrow, &res);
+    cpu->v ^= __builtin_sub_overflow(res, borrow, &res);
     cpu->c = !__builtin_sub_overflow(x, y, &x);
     cpu->c &= !__builtin_sub_overflow(x, borrow, &x);
     return arm_movs(cpu, x);