Why does calling my MIPS matrix multiplication function cause my PSP to crash?

Question

I've been trying to learn how to use the PlayStation Portable's (PSP) vector floating-point unit (vfpu), and I decided the first thing to write for it would be a simple matrix multiplication function that multiplies 2 4x4 matrices. However, the program will instead hang up and then the PSP will shut off.

Here are the two main files: main.c

#include <pspdebug.h>
#include <pspdisplay.h>

#include "../include/callbacks.h"
#include "../include/matrixmul.h"

PSP_MODULE_INFO("vfputest", PSP_MODULE_USER, 1, 0);
PSP_MAIN_THREAD_ATTR(PSP_THREAD_ATTR_USER | PSP_THREAD_ATTR_VFPU);

int main(int argc, char** argv){
    float m0[] = {5, 5, 5, 5, 6, 6, 6, 6, 7, 7, 7, 7, 8, 8, 8, 8};
    float m1[] = {5, 5, 5, 5, 6, 6, 6, 6, 7, 7, 7, 7, 8, 8, 8, 8};
    float m2[16] = {};

    matrixmul4x4(m0, m1, m2);

    setupCallbacks();
    pspDebugScreenInit();

    for(int i = 0; i < 16; i++){
            pspDebugScreenPrintf("m2[%d]: %f\n", i, m2[i]);

    }

    sceKernelSleepThread();

    return 0;
}

matrixmul.s

.globl matrixmul4x4
# $a0 = mat0 address
# $a1 = mat1 address
# $a2 = result address
matrixmul4x4:
.macro lm4 mnum adr
    lv.q r\mnum\()00, 0(\adr\())
    lv.q r\mnum\()01, 16(\adr\())
    lv.q r\mnum\()02, 32(\adr\())
    lv.q r\mnum\()03, 48(\adr\())
.endm
.macro sm4 mnum adr
    sv.q r\mnum\()00, 0(\adr\())
    sv.q r\mnum\()01, 16(\adr\())
    sv.q r\mnum\()02, 32(\adr\())
    sv.q r\mnum\()02, 48(\adr\())
.endm

    lm4 0, $a0  # load mat0
    lm4 1, $a1  # load mat1

    vmmul.q m200, m000, m100    # multiply matrices

    sm4 2, $a2  # store result

    jr $ra

There is a third file, callbacks.c, but all that does at the moment is enable the PSP's home button functionality.

Finally there's my CMakeLists.txt

cmake_minimum_required(VERSION 3.27.3)

project(psp-vfputhing)

add_executable(vfputhing
    src/main.c
    src/callbacks.c
)

target_include_directories(vfputhing PRIVATE include)
target_link_directories(vfputhing PRIVATE src)

if(PLATFORM_PSP)
    create_pbp_file(
        TARGET vfputhing
        TITLE "Dingus Console"
        ICON_PATH NULL
        PREVIEW_PATH NULL
        BUILD_PRX
    )

    target_link_libraries(vfputhing matrixmul pspdebug pspdisplay pspge pspgu pspgum)
endif()

My first attempt at compilation gave me a linker error, telling me there was an undefined reference to matrixmul4x4. I then tried packaging it into a library, which made the linker error go away, but the PSP will crash any time the function is called. What I expected from this function was for it to place the values of the result matrix into the result array and then for the array to be printed out.