r300/compiler: New dataflow structures and passes

This replaces the old NQSSADCE code with the same functionality, but quite
different design. Instead of doing a single integerated pass, we now build
explicit data structures representing the dataflow.

This will enable analysis of flow control instruction, and could potentially
open an avenue for several dataflow based optimizations, such as peephole
optimization, fusing MUL+ADD to MAD, and so on.

1 files changed, 35 insertions, 0 deletions

diff --git a/src/mesa/drivers/dri/r300/compiler/radeon_compiler.c b/src/mesa/drivers/dri/r300/compiler/radeon_compiler.c
index babdcffd3a..d0b78ec1c8 100644
--- a/src/mesa/drivers/dri/r300/compiler/radeon_compiler.c
+++ b/src/mesa/drivers/dri/r300/compiler/radeon_compiler.c
@@ -93,6 +93,41 @@ void rc_error(struct radeon_compiler * c, const char * fmt, ...)
 	}
 }
 
+int rc_if_fail_helper(struct radeon_compiler * c, const char * file, int line, const char * assertion)
+{
+	rc_error(c, "ICE at %s:%i: assertion failed: %s\n", file, line, assertion);
+	return 1;
+}
+
+/**
+ * Recompute c->Program.InputsRead and c->Program.OutputsWritten
+ * based on which inputs and outputs are actually referenced
+ * in program instructions.
+ */
+void rc_calculate_inputs_outputs(struct radeon_compiler * c)
+{
+	struct rc_instruction *inst;
+
+	c->Program.InputsRead = 0;
+	c->Program.OutputsWritten = 0;
+
+	for(inst = c->Program.Instructions.Next; inst != &c->Program.Instructions; inst = inst->Next)
+	{
+		const struct rc_opcode_info * opcode = rc_get_opcode_info(inst->I.Opcode);
+		int i;
+
+		for (i = 0; i < opcode->NumSrcRegs; ++i) {
+			if (inst->I.SrcReg[i].File == RC_FILE_INPUT)
+				c->Program.InputsRead |= 1 << inst->I.SrcReg[i].Index;
+		}
+
+		if (opcode->HasDstReg) {
+			if (inst->I.DstReg.File == RC_FILE_OUTPUT)
+				c->Program.OutputsWritten |= 1 << inst->I.DstReg.Index;
+		}
+	}
+}
+
 /**
  * Rewrite the program such that everything that source the given input
  * register will source new_input instead.