r300/compiler: implement and lower OPCODE_CLAMP

Needed for st/vega.

3 files changed, 28 insertions, 0 deletions

diff --git a/src/mesa/drivers/dri/r300/compiler/radeon_opcodes.c b/src/mesa/drivers/dri/r300/compiler/radeon_opcodes.c
index da495a3afa..113b27632a 100644
--- a/src/mesa/drivers/dri/r300/compiler/radeon_opcodes.c
+++ b/src/mesa/drivers/dri/r300/compiler/radeon_opcodes.c
@@ -67,6 +67,13 @@ struct rc_opcode_info rc_opcodes[MAX_RC_OPCODE] = {
 		.IsComponentwise = 1
 	},
 	{
+		.Opcode = RC_OPCODE_CLAMP,
+		.Name = "CLAMP",
+		.NumSrcRegs = 3,
+		.HasDstReg = 1,
+		.IsComponentwise = 1
+	},
+	{
 		.Opcode = RC_OPCODE_CMP,
 		.Name = "CMP",
 		.NumSrcRegs = 3,
diff --git a/src/mesa/drivers/dri/r300/compiler/radeon_opcodes.h b/src/mesa/drivers/dri/r300/compiler/radeon_opcodes.h
index d3f639c870..7e66610127 100644
--- a/src/mesa/drivers/dri/r300/compiler/radeon_opcodes.h
+++ b/src/mesa/drivers/dri/r300/compiler/radeon_opcodes.h
@@ -50,6 +50,9 @@ typedef enum {
 	/** vec4 instruction: dst.c = ceil(src0.c) */
 	RC_OPCODE_CEIL,
 
+	/** vec4 instruction: dst.c = clamp(src0.c, src1.c, src2.c) */
+	RC_OPCODE_CLAMP,
+
 	/** vec4 instruction: dst.c = src0.c < 0.0 ? src1.c : src2.c */
 	RC_OPCODE_CMP,
 
diff --git a/src/mesa/drivers/dri/r300/compiler/radeon_program_alu.c b/src/mesa/drivers/dri/r300/compiler/radeon_program_alu.c
index 106e03495d..01c2e74e7b 100644
--- a/src/mesa/drivers/dri/r300/compiler/radeon_program_alu.c
+++ b/src/mesa/drivers/dri/r300/compiler/radeon_program_alu.c
@@ -217,6 +217,22 @@ static void transform_CEIL(struct radeon_compiler* c,
 	rc_remove_instruction(inst);
 }
 
+static void transform_CLAMP(struct radeon_compiler *c,
+	struct rc_instruction *inst)
+{
+	/* CLAMP dst, src, min, max
+	 *    into:
+	 * MIN tmp, src, max
+	 * MAX dst, tmp, min
+	 */
+	int tempreg = rc_find_free_temporary(c);
+	emit2(c, inst->Prev, RC_OPCODE_MIN, 0, dstreg(RC_FILE_TEMPORARY, tempreg),
+		inst->U.I.SrcReg[0], inst->U.I.SrcReg[2]);
+	emit2(c, inst->Prev, RC_OPCODE_MAX, inst->U.I.SaturateMode, inst->U.I.DstReg,
+		srcreg(RC_FILE_TEMPORARY, tempreg), inst->U.I.SrcReg[1]);
+	rc_remove_instruction(inst);
+}
+
 static void transform_DP2(struct radeon_compiler* c,
 	struct rc_instruction* inst)
 {
@@ -554,6 +570,7 @@ int radeonTransformALU(
 	switch(inst->U.I.Opcode) {
 	case RC_OPCODE_ABS: transform_ABS(c, inst); return 1;
 	case RC_OPCODE_CEIL: transform_CEIL(c, inst); return 1;
+	case RC_OPCODE_CLAMP: transform_CLAMP(c, inst); return 1;
 	case RC_OPCODE_DP2: transform_DP2(c, inst); return 1;
 	case RC_OPCODE_DPH: transform_DPH(c, inst); return 1;
 	case RC_OPCODE_DST: transform_DST(c, inst); return 1;
@@ -782,6 +799,7 @@ int r300_transform_vertex_alu(
 	switch(inst->U.I.Opcode) {
 	case RC_OPCODE_ABS: transform_r300_vertex_ABS(c, inst); return 1;
 	case RC_OPCODE_CEIL: transform_CEIL(c, inst); return 1;
+	case RC_OPCODE_CLAMP: transform_CLAMP(c, inst); return 1;
 	case RC_OPCODE_CMP: transform_r300_vertex_CMP(c, inst); return 1;
 	case RC_OPCODE_DP2: transform_r300_vertex_DP2(c, inst); return 1;
 	case RC_OPCODE_DP3: transform_r300_vertex_DP3(c, inst); return 1;