Actually the assembly output from objdump isn't quite accurate.
Here's the generated assembly from the compiler.
LDC
---
ldc2 -conf= -disable-simplify-libcalls -c -Os
-mtriple=thumb-none-eabi -float-abi=hard -mcpu=cortex-m4
-Isource/runtime -boundscheck=off
_D5board3lcd8fillRectFiikktZv:
.fnstart
.save {r4, r5, r6, r7, r8, r9, lr}
push.w {r4, r5, r6, r7, r8, r9, lr}
add.w lr, r3, r1
cmp lr, r3
it lt
poplt.w {r4, r5, r6, r7, r8, r9, pc}
ldr.w r12, [sp, #28]
rsb r5, r3, r3, lsl #4
movw r8, :lower16:_D5board4ltdc11frameBufferG76800t
and r1, r2, #3
sub.w r9, r2, #1
movt r8, :upper16:_D5board4ltdc11frameBufferG76800t
subs r4, r2, r1
add.w r5, r12, r5, lsl #4
add.w r5, r8, r5, lsl #1
adds r7, r5, #4
.LBB1_1:
cbz r2, .LBB1_8
movs r5, #0
cmp.w r9, #3
blo .LBB1_5
mov r6, r7
.LBB1_4:
adds r5, #4
strh r0, [r6, #-2]
strh r0, [r6, #-4]
strh r0, [r6]
strh r0, [r6, #2]
adds r6, #8
cmp r4, r5
bne .LBB1_4
.LBB1_5:
cbz r1, .LBB1_8
rsb r6, r3, r3, lsl #4
cmp r1, #1
add.w r6, r12, r6, lsl #4
add r5, r6
strh.w r0, [r8, r5, lsl #1]
beq .LBB1_8
add.w r5, r8, r5, lsl #1
cmp r1, #2
strh r0, [r5, #2]
it ne
strhne r0, [r5, #4]
.LBB1_8:
adds r3, #1
add.w r7, r7, #480
cmp r3, lr
ble .LBB1_1
pop.w {r4, r5, r6, r7, r8, r9, pc}
GDC
---
arm-none-eabi-gdc -c -O2 -nophoboslib -nostdinc -nodefaultlibs
-nostdlib -mthumb -mcpu=cortex-m4 -mtune=cortex-m4
-mfloat-abi=hard -Isource/runtime -fno-bounds-check
-ffunction-sections -fdata-sections -fno-weak
_D5board3lcd8fillRectFiikktZv:
.fnstart
.LFB4:
@ args = 4, pretend = 0, frame = 0
@ frame_needed = 0, uses_anonymous_args = 0
@ link register save eliminated.
push {r4, r5, r6}
add r3, r3, r1
cmp r1, r3
ldrh r5, [sp, #12]
bgt .L47
rsb r4, r1, r1, lsl #4
add r0, r0, r4, lsl #4
ldr r4, .L58
add r0, r0, r2
rsb r6, r2, r2, lsl #31
add r4, r4, r0, lsl #1
lsls r6, r6, #1
.L51:
cbz r2, .L49
adds r0, r4, r6
.L50:
strh r5, [r0], #2 @ movhi
cmp r0, r4
bne .L50
.L49:
adds r1, r1, #1
cmp r3, r1
add r4, r4, #480
bge .L51
.L47:
pop {r4, r5, r6}
bx lr
Mike
