i965g: re-starting from the dri driver

1 files changed, 343 insertions, 0 deletions

diff --git a/src/gallium/drivers/i965/brw_wm_pass2.c b/src/gallium/drivers/i965/brw_wm_pass2.c
new file mode 100644
index 00000000000..6faea018fbc
--- /dev/null
+++ b/src/gallium/drivers/i965/brw_wm_pass2.c
@@ -0,0 +1,343 @@
+/*
+ Copyright (C) Intel Corp.  2006.  All Rights Reserved.
+ Intel funded Tungsten Graphics (http://www.tungstengraphics.com) to
+ develop this 3D driver.
+ 
+ Permission is hereby granted, free of charge, to any person obtaining
+ a copy of this software and associated documentation files (the
+ "Software"), to deal in the Software without restriction, including
+ without limitation the rights to use, copy, modify, merge, publish,
+ distribute, sublicense, and/or sell copies of the Software, and to
+ permit persons to whom the Software is furnished to do so, subject to
+ the following conditions:
+ 
+ The above copyright notice and this permission notice (including the
+ next paragraph) shall be included in all copies or substantial
+ portions of the Software.
+ 
+ THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ IN NO EVENT SHALL THE COPYRIGHT OWNER(S) AND/OR ITS SUPPLIERS BE
+ LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+ OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ 
+ **********************************************************************/
+ /*
+  * Authors:
+  *   Keith Whitwell <[email protected]>
+  */
+                   
+
+#include "brw_context.h"
+#include "brw_wm.h"
+
+
+/* Use these to force spilling so that that functionality can be
+ * tested with known-good examples rather than having to construct new
+ * tests.
+ */
+#define TEST_PAYLOAD_SPILLS 0
+#define TEST_DST_SPILLS 0
+
+static void spill_value(struct brw_wm_compile *c,
+			struct brw_wm_value *value);
+
+static void prealloc_reg(struct brw_wm_compile *c,
+			 struct brw_wm_value *value,
+			 GLuint reg)
+{
+   if (value->lastuse) {
+      /* Set nextuse to zero, it will be corrected by
+       * update_register_usage().
+       */
+      c->pass2_grf[reg].value = value;
+      c->pass2_grf[reg].nextuse = 0;
+
+      value->resident = &c->pass2_grf[reg];
+      value->hw_reg = brw_vec8_grf(reg*2, 0);
+
+      if (TEST_PAYLOAD_SPILLS)
+	 spill_value(c, value);
+   }
+}
+
+
+/* Initialize all the register values.  Do the initial setup
+ * calculations for interpolants.
+ */
+static void init_registers( struct brw_wm_compile *c )
+{
+   GLuint nr_interp_regs = 0;
+   GLuint i = 0;
+   GLuint j;
+
+   for (j = 0; j < c->grf_limit; j++) 
+      c->pass2_grf[j].nextuse = BRW_WM_MAX_INSN;
+
+   for (j = 0; j < c->key.nr_depth_regs; j++) 
+      prealloc_reg(c, &c->payload.depth[j], i++);
+
+   for (j = 0; j < c->nr_creg; j++) 
+      prealloc_reg(c, &c->creg[j], i++);
+
+   for (j = 0; j < FRAG_ATTRIB_MAX; j++) {
+      if (c->key.vp_outputs_written & (1<<j)) {
+	 int fp_index;
+
+	 if (j >= VERT_RESULT_VAR0)
+	    fp_index = j - (VERT_RESULT_VAR0 - FRAG_ATTRIB_VAR0);
+	 else if (j <= VERT_RESULT_TEX7)
+	    fp_index = j;
+	 else
+	    fp_index = -1;
+
+	 nr_interp_regs++;
+	 if (fp_index >= 0)
+	    prealloc_reg(c, &c->payload.input_interp[fp_index], i++);
+      }
+   }
+
+   assert(nr_interp_regs >= 1);
+
+   c->prog_data.first_curbe_grf = c->key.nr_depth_regs * 2;
+   c->prog_data.urb_read_length = nr_interp_regs * 2;
+   c->prog_data.curb_read_length = c->nr_creg * 2;
+
+   c->max_wm_grf = i * 2;
+}
+
+
+/* Update the nextuse value for each register in our file.
+ */
+static void update_register_usage(struct brw_wm_compile *c,
+				  GLuint thisinsn)
+{
+   GLuint i;
+
+   for (i = 1; i < c->grf_limit; i++) {
+      struct brw_wm_grf *grf = &c->pass2_grf[i];
+
+      /* Only search those which can change:
+       */
+      if (grf->nextuse < thisinsn) {
+	 const struct brw_wm_ref *ref = grf->value->lastuse;
+
+	 /* Has last use of value been passed?
+	  */
+	 if (ref->insn < thisinsn) {
+	    grf->value->resident = 0;
+	    grf->value = 0;
+	    grf->nextuse = BRW_WM_MAX_INSN;
+	 }
+	 else {
+	    /* Else loop through chain to update:
+	     */
+	    while (ref->prevuse && ref->prevuse->insn >= thisinsn)
+	       ref = ref->prevuse;
+
+	    grf->nextuse = ref->insn;
+	 }
+      }
+   }
+}
+
+
+static void spill_value(struct brw_wm_compile *c,
+			struct brw_wm_value *value)
+{	
+   /* Allocate a spill slot.  Note that allocations start from 0x40 -
+    * the first slot is reserved to mean "undef" in brw_wm_emit.c
+    */
+   if (!value->spill_slot) {
+      c->last_scratch += 0x40;	
+      value->spill_slot = c->last_scratch;
+   }
+
+   /* The spill will be done in brw_wm_emit.c immediately after the
+    * value is calculated, so we can just take this reg without any
+    * further work.
+    */
+   value->resident->value = NULL;
+   value->resident->nextuse = BRW_WM_MAX_INSN;
+   value->resident = NULL;
+}
+
+
+
+/* Search for contiguous region with the most distant nearest
+ * member.  Free regs count as very distant.
+ *
+ * TODO: implement spill-to-reg so that we can rearrange discontigous
+ * free regs and then spill the oldest non-free regs in sequence.
+ * This would mean inserting instructions in this pass.
+ */
+static GLuint search_contiguous_regs(struct brw_wm_compile *c,
+				     GLuint nr,
+				     GLuint thisinsn)
+{
+   struct brw_wm_grf *grf = c->pass2_grf;
+   GLuint furthest = 0;
+   GLuint reg = 0;
+   GLuint i, j;
+
+   /* Start search at 1: r0 is special and can't be used or spilled.
+    */
+   for (i = 1; i < c->grf_limit && furthest < BRW_WM_MAX_INSN; i++) {
+      GLuint group_nextuse = BRW_WM_MAX_INSN;
+
+      for (j = 0; j < nr; j++) {
+	 if (grf[i+j].nextuse < group_nextuse)
+	    group_nextuse = grf[i+j].nextuse;
+      }
+
+      if (group_nextuse > furthest) {
+	 furthest = group_nextuse;
+	 reg = i;
+      }
+   }
+
+   assert(furthest != thisinsn);
+
+   /* Any non-empty regs will need to be spilled:
+    */
+   for (j = 0; j < nr; j++) 
+      if (grf[reg+j].value)
+	 spill_value(c, grf[reg+j].value);
+
+   return reg;
+}
+
+
+static void alloc_contiguous_dest(struct brw_wm_compile *c, 
+				  struct brw_wm_value *dst[],
+				  GLuint nr,
+				  GLuint thisinsn)
+{
+   GLuint reg = search_contiguous_regs(c, nr, thisinsn);
+   GLuint i;
+
+   for (i = 0; i < nr; i++) {
+      if (!dst[i]) {
+	 /* Need to grab a dummy value in TEX case.  Don't introduce
+	  * it into the tracking scheme.
+	  */
+	 dst[i] = &c->vreg[c->nr_vreg++];
+      }
+      else {
+	 assert(!dst[i]->resident);
+	 assert(c->pass2_grf[reg+i].nextuse != thisinsn);
+
+	 c->pass2_grf[reg+i].value = dst[i];
+	 c->pass2_grf[reg+i].nextuse = thisinsn;
+
+	 dst[i]->resident = &c->pass2_grf[reg+i];
+      }
+
+      dst[i]->hw_reg = brw_vec8_grf((reg+i)*2, 0);
+   }
+
+   if ((reg+nr)*2 > c->max_wm_grf)
+      c->max_wm_grf = (reg+nr) * 2;
+}
+
+
+static void load_args(struct brw_wm_compile *c, 
+		      struct brw_wm_instruction *inst)
+{
+   GLuint thisinsn = inst - c->instruction;
+   GLuint i,j;
+
+   for (i = 0; i < 3; i++) {
+      for (j = 0; j < 4; j++) {
+	 struct brw_wm_ref *ref = inst->src[i][j];
+
+	 if (ref) {
+	    if (!ref->value->resident) {
+	       /* Need to bring the value in from scratch space.  The code for
+		* this will be done in brw_wm_emit.c, here we just do the
+		* register allocation and mark the ref as requiring a fill.
+		*/
+	       GLuint reg = search_contiguous_regs(c, 1, thisinsn);
+
+	       c->pass2_grf[reg].value = ref->value;
+	       c->pass2_grf[reg].nextuse = thisinsn;
+
+	       ref->value->resident = &c->pass2_grf[reg];
+
+	       /* Note that a fill is required:
+		*/
+	       ref->unspill_reg = reg*2;
+	    }
+
+	    /* Adjust the hw_reg to point at the value's current location:
+	     */
+	    assert(ref->value == ref->value->resident->value);
+	    ref->hw_reg.nr += (ref->value->resident - c->pass2_grf) * 2;
+	 }
+      }
+   }
+}
+
+
+
+/* Step 3: Work forwards once again.  Perform register allocations,
+ * taking into account instructions like TEX which require contiguous
+ * result registers.  Where necessary spill registers to scratch space
+ * and reload later.
+ */
+void brw_wm_pass2( struct brw_wm_compile *c )
+{
+   GLuint insn;
+   GLuint i;
+
+   init_registers(c);
+
+   for (insn = 0; insn < c->nr_insns; insn++) {
+      struct brw_wm_instruction *inst = &c->instruction[insn];
+
+      /* Update registers' nextuse values:
+       */
+      update_register_usage(c, insn);
+
+      /* May need to unspill some args.
+       */
+      load_args(c, inst);
+
+      /* Allocate registers to hold results:
+       */
+      switch (inst->opcode) {
+      case OPCODE_TEX:
+      case OPCODE_TXB:
+      case OPCODE_TXP:
+	 alloc_contiguous_dest(c, inst->dst, 4, insn);
+	 break;
+
+      default:
+	 for (i = 0; i < 4; i++) {
+	    if (inst->writemask & (1<<i)) {
+	       assert(inst->dst[i]);
+	       alloc_contiguous_dest(c, &inst->dst[i], 1, insn);
+	    }
+	 }
+	 break;
+      }
+
+      if (TEST_DST_SPILLS && inst->opcode != WM_PIXELXY) {
+	 for (i = 0; i < 4; i++)	
+	    if (inst->dst[i])
+	       spill_value(c, inst->dst[i]);
+      }
+   }
+
+   if (INTEL_DEBUG & DEBUG_WM) {
+      brw_wm_print_program(c, "pass2");
+   }
+
+   c->state = PASS2_DONE;
+
+   if (INTEL_DEBUG & DEBUG_WM) {
+       brw_wm_print_program(c, "pass2/done");
+   }
+}