Mesa (master): r600g: Added preliminary support for the LOG opcode.

[Dave Airlie]

Module: Mesa
Branch: master
Commit: 460c5304aba646143938b76d536a6fc13a302ca8
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=460c5304aba646143938b76d536a6fc13a302ca8

Author: Tilman Sauerbeck <tilman at code-monkey.de>
Date:   Tue Sep  7 11:37:56 2010 +0200

r600g: Added preliminary support for the LOG opcode.

Signed-off-by: Dave Airlie <airlied at redhat.com>

---

 src/gallium/drivers/r600/r600_shader.c |  122 +++++++++++++++++++++++++++++++-
 1 files changed, 121 insertions(+), 1 deletions(-)

diff --git a/src/gallium/drivers/r600/r600_shader.c b/src/gallium/drivers/r600/r600_shader.c
index 11cabdf..6612b0e 100644
--- a/src/gallium/drivers/r600/r600_shader.c
+++ b/src/gallium/drivers/r600/r600_shader.c
@@ -2033,6 +2033,126 @@ static int tgsi_exp(struct r600_shader_ctx *ctx)
 	return tgsi_helper_copy(ctx, inst);
 }
 
+static int tgsi_log(struct r600_shader_ctx *ctx)
+{
+	struct tgsi_full_instruction *inst = &ctx->parse.FullToken.FullInstruction;
+	struct r600_bc_alu_src r600_src[3];
+	struct r600_bc_alu alu;
+	int r;
+
+	/* result.x = floor(log2(src)); */
+	if (inst->Dst[0].Register.WriteMask & 1) {
+		memset(&alu, 0, sizeof(struct r600_bc_alu));
+
+		alu.inst = CTX_INST(V_SQ_ALU_WORD1_OP2_SQ_OP2_INST_LOG_IEEE);
+		r = tgsi_src(ctx, &inst->Src[0], &alu.src[0]);
+		if (r)
+			return r;
+
+		alu.src[0].chan = tgsi_chan(&inst->Src[0], 0);
+
+		alu.dst.sel = ctx->temp_reg;
+		alu.dst.chan = 0;
+		alu.dst.write = 1;
+		alu.last = 1;
+		r = r600_bc_add_alu(ctx->bc, &alu);
+		if (r)
+			return r;
+
+		r = r600_bc_add_literal(ctx->bc, ctx->value);
+		if (r)
+			return r;
+
+		alu.inst = CTX_INST(V_SQ_ALU_WORD1_OP2_SQ_OP2_INST_FLOOR);
+		alu.src[0].sel = ctx->temp_reg;
+		alu.src[0].chan = 0;
+
+		alu.dst.sel = ctx->temp_reg;
+		alu.dst.chan = 0;
+		alu.dst.write = 1;
+		alu.last = 1;
+
+		r = r600_bc_add_alu(ctx->bc, &alu);
+		if (r)
+			return r;
+
+		r = r600_bc_add_literal(ctx->bc, ctx->value);
+		if (r)
+			return r;
+	}
+
+	/* result.y = FIXME; */
+	if ((inst->Dst[0].Register.WriteMask >> 1) & 1) {
+		memset(&alu, 0, sizeof(struct r600_bc_alu));
+
+		alu.inst = CTX_INST(V_SQ_ALU_WORD1_OP2_SQ_OP2_INST_MOV);
+		alu.src[0].sel = V_SQ_ALU_SRC_1;
+		alu.src[0].chan = 0;
+
+		alu.dst.sel = ctx->temp_reg;
+		alu.dst.chan = 1;
+		alu.dst.write = 1;
+		alu.last = 1;
+
+		r = r600_bc_add_alu(ctx->bc, &alu);
+		if (r)
+			return r;
+
+		r = r600_bc_add_literal(ctx->bc, ctx->value);
+		if (r)
+			return r;
+	}
+
+	/* result.z = log2(src);*/
+	if ((inst->Dst[0].Register.WriteMask >> 2) & 1) {
+		memset(&alu, 0, sizeof(struct r600_bc_alu));
+
+		alu.inst = CTX_INST(V_SQ_ALU_WORD1_OP2_SQ_OP2_INST_LOG_IEEE);
+		r = tgsi_src(ctx, &inst->Src[0], &alu.src[0]);
+		if (r)
+			return r;
+
+		alu.src[0].chan = tgsi_chan(&inst->Src[0], 0);
+
+		alu.dst.sel = ctx->temp_reg;
+		alu.dst.write = 1;
+		alu.dst.chan = 2;
+		alu.last = 1;
+
+		r = r600_bc_add_alu(ctx->bc, &alu);
+		if (r)
+			return r;
+
+		r = r600_bc_add_literal(ctx->bc, ctx->value);
+		if (r)
+			return r;
+	}
+
+	/* result.w = 1.0; */
+	if ((inst->Dst[0].Register.WriteMask >> 3) & 1) {
+		memset(&alu, 0, sizeof(struct r600_bc_alu));
+
+		alu.inst = CTX_INST(V_SQ_ALU_WORD1_OP2_SQ_OP2_INST_MOV);
+		alu.src[0].sel = V_SQ_ALU_SRC_1;
+		alu.src[0].chan = 0;
+
+		alu.dst.sel = ctx->temp_reg;
+		alu.dst.chan = 3;
+		alu.dst.write = 1;
+		alu.last = 1;
+
+		r = r600_bc_add_alu(ctx->bc, &alu);
+		if (r)
+			return r;
+
+		r = r600_bc_add_literal(ctx->bc, ctx->value);
+		if (r)
+			return r;
+	}
+
+	return tgsi_helper_copy(ctx, inst);
+}
+
 static int tgsi_arl(struct r600_shader_ctx *ctx)
 {
 	/* TODO from r600c, ar values don't persist between clauses */
@@ -2380,7 +2500,7 @@ static struct r600_shader_tgsi_instruction r600_shader_tgsi_instruction[] = {
 	{TGSI_OPCODE_RCP,	0, V_SQ_ALU_WORD1_OP2_SQ_OP2_INST_RECIP_IEEE, tgsi_trans_srcx_replicate},
 	{TGSI_OPCODE_RSQ,	0, V_SQ_ALU_WORD1_OP2_SQ_OP2_INST_NOP, tgsi_rsq},
 	{TGSI_OPCODE_EXP,	0, V_SQ_ALU_WORD1_OP2_SQ_OP2_INST_NOP, tgsi_exp},
-	{TGSI_OPCODE_LOG,	0, V_SQ_ALU_WORD1_OP2_SQ_OP2_INST_NOP, tgsi_unsupported},
+	{TGSI_OPCODE_LOG,	0, V_SQ_ALU_WORD1_OP2_SQ_OP2_INST_NOP, tgsi_log},
 	{TGSI_OPCODE_MUL,	0, V_SQ_ALU_WORD1_OP2_SQ_OP2_INST_MUL, tgsi_op2},
 	{TGSI_OPCODE_ADD,	0, V_SQ_ALU_WORD1_OP2_SQ_OP2_INST_ADD, tgsi_op2},
 	{TGSI_OPCODE_DP3,	0, V_SQ_ALU_WORD1_OP2_SQ_OP2_INST_DOT4, tgsi_dp},