etnaviv: Use the correct LOG instruction on GC3000

GC3000 has a new LOG instruction, similar to the new SIN and COS instructions.

Generate the new instruction sequence when appropriate; there are
two occasions, as part of LIT and the generator for the LG2
instruction itself.

Signed-off-by: Wladimir J. van der Laan <[email protected]>
Reviewed-by: Lucas Stach <[email protected]>

3 files changed, 59 insertions, 10 deletions

diff --git a/src/gallium/drivers/etnaviv/etnaviv_compiler.c b/src/gallium/drivers/etnaviv/etnaviv_compiler.c
index 2e8dd8643a5..cc6bfc9425d 100644
--- a/src/gallium/drivers/etnaviv/etnaviv_compiler.c
+++ b/src/gallium/drivers/etnaviv/etnaviv_compiler.c
@@ -1391,12 +1391,27 @@ trans_lit(const struct instr_translater *t, struct etna_compile *c,
    else
       src_w = swizzle(src[0], SWIZZLE(W, W, W, W));
 
-   struct etna_inst ins[3] = { };
-   ins[0].opcode = INST_OPCODE_LOG;
-   ins[0].dst = etna_native_to_dst(inner_temp, INST_COMPS_X);
-   ins[0].src[2] = src_y;
+   if (c->specs->has_new_transcendentals) { /* Alternative LOG sequence */
+      emit_inst(c, &(struct etna_inst) {
+         .opcode = INST_OPCODE_LOG,
+         .dst = etna_native_to_dst(inner_temp, INST_COMPS_X | INST_COMPS_Y),
+         .src[2] = src_y,
+         .tex = { .amode=1 }, /* Unknown bit needs to be set */
+      });
+      emit_inst(c, &(struct etna_inst) {
+         .opcode = INST_OPCODE_MUL,
+         .dst = etna_native_to_dst(inner_temp, INST_COMPS_X),
+         .src[0] = etna_native_to_src(inner_temp, SWIZZLE(X, X, X, X)),
+         .src[1] = etna_native_to_src(inner_temp, SWIZZLE(Y, Y, Y, Y)),
+      });
+   } else {
+      struct etna_inst ins[3] = { };
+      ins[0].opcode = INST_OPCODE_LOG;
+      ins[0].dst = etna_native_to_dst(inner_temp, INST_COMPS_X);
+      ins[0].src[2] = src_y;
 
-   emit_inst(c, &ins[0]);
+      emit_inst(c, &ins[0]);
+   }
    emit_inst(c, &(struct etna_inst) {
       .opcode = INST_OPCODE_MUL,
       .sat = 0,
@@ -1452,7 +1467,7 @@ static void
 trans_trig(const struct instr_translater *t, struct etna_compile *c,
            const struct tgsi_full_instruction *inst, struct etna_inst_src *src)
 {
-   if (c->specs->has_new_sin_cos) { /* Alternative SIN/COS */
+   if (c->specs->has_new_transcendentals) { /* Alternative SIN/COS */
       /* On newer chips alternative SIN/COS instructions are implemented,
        * which:
        * - Need their input scaled by 1/pi instead of 2/pi
@@ -1615,6 +1630,40 @@ trans_trig(const struct instr_translater *t, struct etna_compile *c,
 }
 
 static void
+trans_lg2(const struct instr_translater *t, struct etna_compile *c,
+            const struct tgsi_full_instruction *inst, struct etna_inst_src *src)
+{
+   if (c->specs->has_new_transcendentals) {
+      /* On newer chips alternative LOG instruction is implemented,
+       * which outputs an x and y component, which need to be multiplied to
+       * get the result.
+       */
+      struct etna_native_reg temp = etna_compile_get_inner_temp(c); /* only using .xy */
+      emit_inst(c, &(struct etna_inst) {
+         .opcode = INST_OPCODE_LOG,
+         .sat = 0,
+         .dst = etna_native_to_dst(temp, INST_COMPS_X | INST_COMPS_Y),
+         .src[2] = src[0],
+         .tex = { .amode=1 }, /* Unknown bit needs to be set */
+      });
+      emit_inst(c, &(struct etna_inst) {
+         .opcode = INST_OPCODE_MUL,
+         .sat = inst->Instruction.Saturate,
+         .dst = convert_dst(c, &inst->Dst[0]),
+         .src[0] = etna_native_to_src(temp, SWIZZLE(X, X, X, X)),
+         .src[1] = etna_native_to_src(temp, SWIZZLE(Y, Y, Y, Y)),
+      });
+   } else {
+      emit_inst(c, &(struct etna_inst) {
+         .opcode = INST_OPCODE_LOG,
+         .sat = inst->Instruction.Saturate,
+         .dst = convert_dst(c, &inst->Dst[0]),
+         .src[2] = src[0],
+      });
+   }
+}
+
+static void
 trans_dph(const struct instr_translater *t, struct etna_compile *c,
           const struct tgsi_full_instruction *inst, struct etna_inst_src *src)
 {
@@ -1755,7 +1804,7 @@ static const struct instr_translater translaters[TGSI_OPCODE_LAST] = {
    INSTR(DST, trans_instr, .opc = INST_OPCODE_DST, .src = {0, 1, -1}),
    INSTR(MAD, trans_instr, .opc = INST_OPCODE_MAD, .src = {0, 1, 2}),
    INSTR(EX2, trans_instr, .opc = INST_OPCODE_EXP, .src = {2, -1, -1}),
-   INSTR(LG2, trans_instr, .opc = INST_OPCODE_LOG, .src = {2, -1, -1}),
+   INSTR(LG2, trans_lg2),
    INSTR(SQRT, trans_instr, .opc = INST_OPCODE_SQRT, .src = {2, -1, -1}),
    INSTR(FRC, trans_instr, .opc = INST_OPCODE_FRC, .src = {2, -1, -1}),
    INSTR(CEIL, trans_instr, .opc = INST_OPCODE_CEIL, .src = {2, -1, -1}),
diff --git a/src/gallium/drivers/etnaviv/etnaviv_internal.h b/src/gallium/drivers/etnaviv/etnaviv_internal.h
index 1212fdfa310..8a311678304 100644
--- a/src/gallium/drivers/etnaviv/etnaviv_internal.h
+++ b/src/gallium/drivers/etnaviv/etnaviv_internal.h
@@ -70,8 +70,8 @@ struct etna_specs {
    unsigned has_sign_floor_ceil : 1;
    /* can use VS_RANGE, PS_RANGE registers*/
    unsigned has_shader_range_registers : 1;
-   /* has the new sin/cos functions */
-   unsigned has_new_sin_cos : 1;
+   /* has the new sin/cos/log functions */
+   unsigned has_new_transcendentals : 1;
    /* supports single-buffer rendering with multiple pixel pipes */
    unsigned single_buffer : 1;
    /* can use any kind of wrapping mode on npot textures */
diff --git a/src/gallium/drivers/etnaviv/etnaviv_screen.c b/src/gallium/drivers/etnaviv/etnaviv_screen.c
index fa0cbd90764..61bae57f74a 100644
--- a/src/gallium/drivers/etnaviv/etnaviv_screen.c
+++ b/src/gallium/drivers/etnaviv/etnaviv_screen.c
@@ -641,7 +641,7 @@ etna_get_specs(struct etna_screen *screen)
       screen->model >= 0x1000 || screen->model == 0x880;
    screen->specs.npot_tex_any_wrap =
       VIV_FEATURE(screen, chipMinorFeatures1, NON_POWER_OF_TWO);
-   screen->specs.has_new_sin_cos =
+   screen->specs.has_new_transcendentals =
       VIV_FEATURE(screen, chipMinorFeatures3, HAS_FAST_TRANSCENDENTALS);
 
    if (VIV_FEATURE(screen, chipMinorFeatures3, INSTRUCTION_CACHE)) {