[Mesa-dev] [PATCH 3/6] i965: Generalize GL_FIXED VS w/a support

[Chris Forbes]

Next few patches build on this to add other workarounds
for packed formats.

Signed-off-by: Chris Forbes <chrisf at ijw.co.nz>
---
 src/mesa/drivers/dri/i965/brw_vec4_visitor.cpp | 14 +++++++-------
 src/mesa/drivers/dri/i965/brw_vs.c             |  9 +++++----
 src/mesa/drivers/dri/i965/brw_vs.h             | 14 +++++++++++---
 src/mesa/drivers/dri/i965/brw_vs_emit.c        | 20 +++++++++++---------
 4 files changed, 34 insertions(+), 23 deletions(-)

diff --git a/src/mesa/drivers/dri/i965/brw_vec4_visitor.cpp b/src/mesa/drivers/dri/i965/brw_vec4_visitor.cpp
index f54c49e..dba0a82 100644
--- a/src/mesa/drivers/dri/i965/brw_vec4_visitor.cpp
+++ b/src/mesa/drivers/dri/i965/brw_vec4_visitor.cpp
@@ -800,13 +800,13 @@ vec4_visitor::visit(ir_variable *ir)
        * come in as floating point conversions of the integer values.
        */
       for (int i = ir->location; i < ir->location + type_size(ir->type); i++) {
-	 if (!c->key.gl_fixed_input_size[i])
-	    continue;
-
-	 dst_reg dst = *reg;
-         dst.type = brw_type_for_base_type(ir->type);
-	 dst.writemask = (1 << c->key.gl_fixed_input_size[i]) - 1;
-	 emit(MUL(dst, src_reg(dst), src_reg(1.0f / 65536.0f)));
+         uint8_t wa_flags = c->key.gl_attrib_wa_flags[i];
+         if (wa_flags & BRW_ATTRIB_WA_COMPONENTS) {
+            dst_reg dst = *reg;
+            dst.type = brw_type_for_base_type(ir->type);
+            dst.writemask = (1 << (wa_flags & BRW_ATTRIB_WA_COMPONENTS)) - 1;
+            emit(MUL(dst, src_reg(dst), src_reg(1.0f / 65536.0f)));
+         }
       }
       break;
 
diff --git a/src/mesa/drivers/dri/i965/brw_vs.c b/src/mesa/drivers/dri/i965/brw_vs.c
index 4e95074..c31092d 100644
--- a/src/mesa/drivers/dri/i965/brw_vs.c
+++ b/src/mesa/drivers/dri/i965/brw_vs.c
@@ -381,9 +381,9 @@ brw_vs_debug_recompile(struct brw_context *brw,
    }
 
    for (unsigned int i = 0; i < VERT_ATTRIB_MAX; i++) {
-      found |= key_debug("GL_FIXED rescaling",
-                         old_key->gl_fixed_input_size[i],
-                         key->gl_fixed_input_size[i]);
+      found |= key_debug("Vertex attrib w/a flags",
+                     old_key->gl_attrib_wa_flags[i],
+                     key->gl_attrib_wa_flags[i]);
    }
 
    found |= key_debug("user clip flags",
@@ -465,9 +465,10 @@ static void brw_upload_vs_prog(struct brw_context *brw)
 
    /* BRW_NEW_VERTICES */
    for (i = 0; i < VERT_ATTRIB_MAX; i++) {
+      /* TODO: flag w/a for packed vertex formats here too */
       if (vp->program.Base.InputsRead & BITFIELD64_BIT(i) &&
 	  brw->vb.inputs[i].glarray->Type == GL_FIXED) {
-	 key.gl_fixed_input_size[i] = brw->vb.inputs[i].glarray->Size;
+	 key.gl_attrib_wa_flags[i] = brw->vb.inputs[i].glarray->Size;
       }
    }
 
diff --git a/src/mesa/drivers/dri/i965/brw_vs.h b/src/mesa/drivers/dri/i965/brw_vs.h
index adeff7f..9da4cb0 100644
--- a/src/mesa/drivers/dri/i965/brw_vs.h
+++ b/src/mesa/drivers/dri/i965/brw_vs.h
@@ -39,13 +39,21 @@
 #include "brw_program.h"
 #include "program/program.h"
 
+/* fixup bits for gl_packed_input_flags,
+ * to enable various VS workarounds */
+#define BRW_ATTRIB_WA_COMPONENTS    7  /* mask for GL_FIXED scale channel count */
+#define BRW_ATTRIB_WA_NORMALIZE     8  /* normalize in shader */
+#define BRW_ATTRIB_WA_BGRA          16 /* swap r/b channels in shader */
+#define BRW_ATTRIB_WA_SIGN          32 /* interpret as signed in shader */
+#define BRW_ATTRIB_WA_SCALE         64 /* interpret as scaled in shader */
 
 struct brw_vs_prog_key {
    GLuint program_string_id;
-   /**
-    * Number of channels of the vertex attribute that need GL_FIXED rescaling
+
+   /*
+    * Per-attribute workaround flags
     */
-   uint8_t gl_fixed_input_size[VERT_ATTRIB_MAX];
+   uint8_t gl_attrib_wa_flags[VERT_ATTRIB_MAX];
 
    /**
     * True if at least one clip flag is enabled, regardless of whether the
diff --git a/src/mesa/drivers/dri/i965/brw_vs_emit.c b/src/mesa/drivers/dri/i965/brw_vs_emit.c
index 02239b4..a4742c7 100644
--- a/src/mesa/drivers/dri/i965/brw_vs_emit.c
+++ b/src/mesa/drivers/dri/i965/brw_vs_emit.c
@@ -1582,22 +1582,24 @@ accumulator_contains(struct brw_vs_compile *c, struct brw_reg val)
 }
 
 static void
-brw_vs_rescale_gl_fixed(struct brw_vs_compile *c)
+brw_vs_apply_attrib_wa(struct brw_vs_compile *c)
 {
    struct brw_compile *p = &c->func;
    int i;
 
    for (i = 0; i < VERT_ATTRIB_MAX; i++) {
+      uint8_t wa_flags = c->key.gl_attrib_wa_flags[i];
       if (!(c->prog_data.inputs_read & BITFIELD64_BIT(i)))
-	 continue;
+         continue;
 
-      if (c->key.gl_fixed_input_size[i] != 0) {
-	 struct brw_reg reg = c->regs[PROGRAM_INPUT][i];
-
-	 brw_MUL(p,
-		 brw_writemask(reg, (1 << c->key.gl_fixed_input_size[i]) - 1),
-		 reg, brw_imm_f(1.0 / 65536.0));
+      if (wa_flags & BRW_ATTRIB_WA_COMPONENTS) {
+         struct brw_reg reg = c->regs[PROGRAM_INPUT][i];
+         brw_MUL(p,
+            brw_writemask(reg, (1 << (wa_flags & BRW_ATTRIB_WA_COMPONENTS)) - 1),
+            reg, brw_imm_f(1.0 / 65536.0));
       }
+
+      /* TODO: emit other packed vertex attrib w/a shader code here. */
    }
 }
 
@@ -1625,7 +1627,7 @@ void brw_old_vs_emit(struct brw_vs_compile *c )
     */
    brw_vs_alloc_regs(c);
 
-   brw_vs_rescale_gl_fixed(c);
+   brw_vs_apply_attrib_wa(c);
 
    for (insn = 0; insn < nr_insns; insn++) {
 
-- 
1.7.12.4