mips/float_dsp: fix a bug in vector_fmul_window_mips

Loop was unrolled eight times although in heder there is assumption
that len is multiple of 4.
This is fixed, and assembly code is rewritten to be more optimal and
to simplify clobber list.

Signed-off-by: Nedeljko Babic <nedeljko.babic@imgtec.com>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

1 files changed, 74 insertions, 106 deletions

diff --git a/libavutil/mips/float_dsp_mips.c b/libavutil/mips/float_dsp_mips.c
index 06d52dc258..a54f959329 100644
--- a/libavutil/mips/float_dsp_mips.c
+++ b/libavutil/mips/float_dsp_mips.c
@@ -144,114 +144,82 @@ static void vector_fmul_scalar_mips(float *dst, const float *src, float mul,
 }
 
 static void vector_fmul_window_mips(float *dst, const float *src0,
-        const float *src1, const float *win, int len)
+                                    const float *src1, const float *win, int len)
 {
-    int i, j;
-    /*
-     * variables used in inline assembler
-     */
-    float * dst_i, * dst_j, * dst_i2, * dst_j2;
-    float temp, temp1, temp2, temp3, temp4, temp5, temp6, temp7;
+    float * dst_j, *win_j, *src0_i, *src1_j, *dst_i, *win_i;
+    float temp, temp1, temp2, temp3;
+    float s0, s01, s1, s11;
+    float wi, wi1, wi2, wi3;
+    float wj, wj1, wj2, wj3;
+    const float * lp_end = win + len;
+
+    win_i  = (float *)win;
+    win_j  = (float *)(win + 2 * len -1);
+    src1_j = (float *)(src1 + len - 1);
+    src0_i = (float *)src0;
+    dst_i  = (float *)dst;
+    dst_j  = (float *)(dst + 2 * len -1);
 
-    dst  += len;
-    win  += len;
-    src0 += len;
-
-    for (i = -len, j = len - 1; i < 0; i += 8, j -= 8) {
-
-        dst_i = dst + i;
-        dst_j = dst + j;
-
-        dst_i2 = dst + i + 4;
-        dst_j2 = dst + j - 4;
-
-        __asm__ volatile (
-            "mul.s   %[temp],   %[s1],       %[wi]            \n\t"
-            "mul.s   %[temp1],  %[s1],       %[wj]            \n\t"
-            "mul.s   %[temp2],  %[s11],      %[wi1]           \n\t"
-            "mul.s   %[temp3],  %[s11],      %[wj1]           \n\t"
-
-            "msub.s  %[temp],   %[temp],     %[s0],  %[wj]    \n\t"
-            "madd.s  %[temp1],  %[temp1],    %[s0],  %[wi]    \n\t"
-            "msub.s  %[temp2],  %[temp2],    %[s01], %[wj1]   \n\t"
-            "madd.s  %[temp3],  %[temp3],    %[s01], %[wi1]   \n\t"
-
-            "swc1    %[temp],   0(%[dst_i])                   \n\t" /* dst[i] = s0*wj - s1*wi; */
-            "swc1    %[temp1],  0(%[dst_j])                   \n\t" /* dst[j] = s0*wi + s1*wj; */
-            "swc1    %[temp2],  4(%[dst_i])                   \n\t" /* dst[i+1] = s01*wj1 - s11*wi1; */
-            "swc1    %[temp3], -4(%[dst_j])                   \n\t" /* dst[j-1] = s01*wi1 + s11*wj1; */
-
-            "mul.s   %[temp4],  %[s12],      %[wi2]           \n\t"
-            "mul.s   %[temp5],  %[s12],      %[wj2]           \n\t"
-            "mul.s   %[temp6],  %[s13],      %[wi3]           \n\t"
-            "mul.s   %[temp7],  %[s13],      %[wj3]           \n\t"
-
-            "msub.s  %[temp4],  %[temp4],    %[s02], %[wj2]   \n\t"
-            "madd.s  %[temp5],  %[temp5],    %[s02], %[wi2]   \n\t"
-            "msub.s  %[temp6],  %[temp6],    %[s03], %[wj3]   \n\t"
-            "madd.s  %[temp7],  %[temp7],    %[s03], %[wi3]   \n\t"
-
-            "swc1    %[temp4],  8(%[dst_i])                   \n\t" /* dst[i+2] = s02*wj2 - s12*wi2; */
-            "swc1    %[temp5], -8(%[dst_j])                   \n\t" /* dst[j-2] = s02*wi2 + s12*wj2; */
-            "swc1    %[temp6],  12(%[dst_i])                  \n\t" /* dst[i+2] = s03*wj3 - s13*wi3; */
-            "swc1    %[temp7], -12(%[dst_j])                  \n\t" /* dst[j-3] = s03*wi3 + s13*wj3; */
-            : [temp]"=&f"(temp),  [temp1]"=&f"(temp1), [temp2]"=&f"(temp2),
-              [temp3]"=&f"(temp3), [temp4]"=&f"(temp4), [temp5]"=&f"(temp5),
-              [temp6]"=&f"(temp6), [temp7]"=&f"(temp7)
-            : [dst_j]"r"(dst_j),     [dst_i]"r" (dst_i),
-              [s0] "f"(src0[i]),     [wj] "f"(win[j]),     [s1] "f"(src1[j]),
-              [wi] "f"(win[i]),      [s01]"f"(src0[i + 1]),[wj1]"f"(win[j - 1]),
-              [s11]"f"(src1[j - 1]), [wi1]"f"(win[i + 1]), [s02]"f"(src0[i + 2]),
-              [wj2]"f"(win[j - 2]),  [s12]"f"(src1[j - 2]),[wi2]"f"(win[i + 2]),
-              [s03]"f"(src0[i + 3]), [wj3]"f"(win[j - 3]), [s13]"f"(src1[j - 3]),
-              [wi3]"f"(win[i + 3])
-            : "memory"
-        );
-
-        __asm__ volatile (
-            "mul.s  %[temp],   %[s1],       %[wi]            \n\t"
-            "mul.s  %[temp1],  %[s1],       %[wj]            \n\t"
-            "mul.s  %[temp2],  %[s11],      %[wi1]           \n\t"
-            "mul.s  %[temp3],  %[s11],      %[wj1]           \n\t"
-
-            "msub.s %[temp],   %[temp],     %[s0],  %[wj]    \n\t"
-            "madd.s %[temp1],  %[temp1],    %[s0],  %[wi]    \n\t"
-            "msub.s %[temp2],  %[temp2],    %[s01], %[wj1]   \n\t"
-            "madd.s %[temp3],  %[temp3],    %[s01], %[wi1]   \n\t"
-
-            "swc1   %[temp],   0(%[dst_i2])                  \n\t" /* dst[i] = s0*wj - s1*wi; */
-            "swc1   %[temp1],  0(%[dst_j2])                  \n\t" /* dst[j] = s0*wi + s1*wj; */
-            "swc1   %[temp2],  4(%[dst_i2])                  \n\t" /* dst[i+1] = s01*wj1 - s11*wi1; */
-            "swc1   %[temp3], -4(%[dst_j2])                  \n\t" /* dst[j-1] = s01*wi1 + s11*wj1; */
-
-            "mul.s  %[temp4],  %[s12],      %[wi2]           \n\t"
-            "mul.s  %[temp5],  %[s12],      %[wj2]           \n\t"
-            "mul.s  %[temp6],  %[s13],      %[wi3]           \n\t"
-            "mul.s  %[temp7],  %[s13],      %[wj3]           \n\t"
-
-            "msub.s %[temp4],  %[temp4],    %[s02], %[wj2]   \n\t"
-            "madd.s %[temp5],  %[temp5],    %[s02], %[wi2]   \n\t"
-            "msub.s %[temp6],  %[temp6],    %[s03], %[wj3]   \n\t"
-            "madd.s %[temp7],  %[temp7],    %[s03], %[wi3]   \n\t"
-
-            "swc1   %[temp4],  8(%[dst_i2])                  \n\t" /* dst[i+2] = s02*wj2 - s12*wi2; */
-            "swc1   %[temp5], -8(%[dst_j2])                  \n\t" /* dst[j-2] = s02*wi2 + s12*wj2; */
-            "swc1   %[temp6],  12(%[dst_i2])                 \n\t" /* dst[i+2] = s03*wj3 - s13*wi3; */
-            "swc1   %[temp7], -12(%[dst_j2])                 \n\t" /* dst[j-3] = s03*wi3 + s13*wj3; */
-            : [temp]"=&f"(temp),
-              [temp1]"=&f"(temp1), [temp2]"=&f"(temp2), [temp3]"=&f"(temp3),
-              [temp4]"=&f"(temp4), [temp5]"=&f"(temp5), [temp6]"=&f"(temp6),
-              [temp7]  "=&f" (temp7)
-            : [dst_j2]"r"(dst_j2),   [dst_i2]"r"(dst_i2),
-              [s0] "f"(src0[i + 4]), [wj] "f"(win[j - 4]), [s1] "f"(src1[j - 4]),
-              [wi] "f"(win[i + 4]),  [s01]"f"(src0[i + 5]),[wj1]"f"(win[j - 5]),
-              [s11]"f"(src1[j - 5]), [wi1]"f"(win[i + 5]), [s02]"f"(src0[i + 6]),
-              [wj2]"f"(win[j - 6]),  [s12]"f"(src1[j - 6]),[wi2]"f"(win[i + 6]),
-              [s03]"f"(src0[i + 7]), [wj3]"f"(win[j - 7]), [s13]"f"(src1[j - 7]),
-              [wi3]"f"(win[i + 7])
-            : "memory"
-        );
-    }
+    /* loop unrolled 4 times */
+    __asm__ volatile (
+        "1:"
+        "lwc1    %[s1],     0(%[src1_j])                \n\t"
+        "lwc1    %[wi],     0(%[win_i])                 \n\t"
+        "lwc1    %[wj],     0(%[win_j])                 \n\t"
+        "lwc1    %[s11],   -4(%[src1_j])                \n\t"
+        "lwc1    %[wi1],    4(%[win_i])                 \n\t"
+        "lwc1    %[wj1],   -4(%[win_j])                 \n\t"
+        "lwc1    %[s0],     0(%[src0_i])                \n\t"
+        "lwc1    %[s01],    4(%[src0_i])                \n\t"
+        "mul.s   %[temp],   %[s1],   %[wi]              \n\t"
+        "mul.s   %[temp1],  %[s1],   %[wj]              \n\t"
+        "mul.s   %[temp2],  %[s11],  %[wi1]             \n\t"
+        "mul.s   %[temp3],  %[s11],  %[wj1]             \n\t"
+        "lwc1    %[s1],    -8(%[src1_j])                \n\t"
+        "lwc1    %[wi2],    8(%[win_i])                 \n\t"
+        "lwc1    %[wj2],   -8(%[win_j])                 \n\t"
+        "lwc1    %[s11],   -12(%[src1_j])               \n\t"
+        "msub.s  %[temp],   %[temp],  %[s0],  %[wj]     \n\t"
+        "madd.s  %[temp1],  %[temp1], %[s0],  %[wi]     \n\t"
+        "msub.s  %[temp2],  %[temp2], %[s01], %[wj1]    \n\t"
+        "madd.s  %[temp3],  %[temp3], %[s01], %[wi1]    \n\t"
+        "lwc1    %[wi3],    12(%[win_i])                \n\t"
+        "lwc1    %[wj3],   -12(%[win_j])                \n\t"
+        "lwc1    %[s0],     8(%[src0_i])                \n\t"
+        "lwc1    %[s01],    12(%[src0_i])               \n\t"
+        "addiu   %[src1_j],-16                          \n\t"
+        "addiu   %[win_i],  16                          \n\t"
+        "addiu   %[win_j], -16                          \n\t"
+        "addiu   %[src0_i], 16                          \n\t"
+        "swc1    %[temp],   0(%[dst_i])                 \n\t" /* dst[i] = s0*wj - s1*wi; */
+        "swc1    %[temp1],  0(%[dst_j])                 \n\t" /* dst[j] = s0*wi + s1*wj; */
+        "swc1    %[temp2],  4(%[dst_i])                 \n\t" /* dst[i+1] = s01*wj1 - s11*wi1; */
+        "swc1    %[temp3], -4(%[dst_j])                 \n\t" /* dst[j-1] = s01*wi1 + s11*wj1; */
+        "mul.s   %[temp],   %[s1],    %[wi2]            \n\t"
+        "mul.s   %[temp1],  %[s1],    %[wj2]            \n\t"
+        "mul.s   %[temp2],  %[s11],   %[wi3]            \n\t"
+        "mul.s   %[temp3],  %[s11],   %[wj3]            \n\t"
+        "msub.s  %[temp],   %[temp],  %[s0],  %[wj2]    \n\t"
+        "madd.s  %[temp1],  %[temp1], %[s0],  %[wi2]    \n\t"
+        "msub.s  %[temp2],  %[temp2], %[s01], %[wj3]    \n\t"
+        "madd.s  %[temp3],  %[temp3], %[s01], %[wi3]    \n\t"
+        "swc1    %[temp],   8(%[dst_i])                 \n\t" /* dst[i+2] = s0*wj2 - s1*wi2; */
+        "swc1    %[temp1], -8(%[dst_j])                 \n\t" /* dst[j-2] = s0*wi2 + s1*wj2; */
+        "swc1    %[temp2],  12(%[dst_i])                \n\t" /* dst[i+2] = s01*wj3 - s11*wi3; */
+        "swc1    %[temp3], -12(%[dst_j])                \n\t" /* dst[j-3] = s01*wi3 + s11*wj3; */
+        "addiu   %[dst_i],  16                          \n\t"
+        "addiu   %[dst_j], -16                          \n\t"
+        "bne     %[win_i], %[lp_end], 1b                \n\t"
+        : [temp]"=&f"(temp), [temp1]"=&f"(temp1), [temp2]"=&f"(temp2),
+          [temp3]"=&f"(temp3), [src0_i]"+r"(src0_i), [win_i]"+r"(win_i),
+          [src1_j]"+r"(src1_j), [win_j]"+r"(win_j), [dst_i]"+r"(dst_i),
+          [dst_j]"+r"(dst_j), [s0] "=&f"(s0), [s01]"=&f"(s01), [s1] "=&f"(s1),
+          [s11]"=&f"(s11), [wi] "=&f"(wi), [wj] "=&f"(wj), [wi2]"=&f"(wi2),
+          [wj2]"=&f"(wj2), [wi3]"=&f"(wi3), [wj3]"=&f"(wj3), [wi1]"=&f"(wi1),
+          [wj1]"=&f"(wj1)
+        : [lp_end]"r"(lp_end)
+        : "memory"
+    );
 }
 
 static void butterflies_float_mips(float *av_restrict v1, float *av_restrict v2,