[Mesa-dev] [PATCH 4/9] mesa: fix validate for secondary interpolator

[Miklós Máté]

This patch fixes multiple problems:
- the interpolator check was duplicated
- both had arg instead of argRep
- I split it into color and alpha for better readability and error msg
- the DOT4 check only applies to color instruction according to the spec
- made the DOT4 check fatal, and improved the error msg

Piglit: spec/ati_fragment_shader/error08-secondary

v2: fixed formatting, added spec quotations

Signed-off-by: Miklós Máté <mtmkls at gmail.com>
---
 src/mesa/main/atifragshader.c | 40 +++++++++++++++++++++++++++-------------
 1 file changed, 27 insertions(+), 13 deletions(-)

diff --git a/src/mesa/main/atifragshader.c b/src/mesa/main/atifragshader.c
index 5ddd83bec4..4aebaf659e 100644
--- a/src/mesa/main/atifragshader.c
+++ b/src/mesa/main/atifragshader.c
@@ -171,15 +171,22 @@ static int check_arith_arg(struct ati_fragment_shader *curProg,
       _mesa_error(ctx, GL_INVALID_ENUM, "C/AFragmentOpATI(arg)");
       return 0;
    }
-   if ((arg == GL_SECONDARY_INTERPOLATOR_ATI) && (((optype == 0) && (argRep == GL_ALPHA)) ||
-      ((optype == 1) && ((arg == GL_ALPHA) || (argRep == GL_NONE))))) {
-      _mesa_error(ctx, GL_INVALID_OPERATION, "C/AFragmentOpATI(sec_interp)");
-      return 0;
-   }
-   if ((arg == GL_SECONDARY_INTERPOLATOR_ATI) && (((optype == 0) && (argRep == GL_ALPHA)) ||
-      ((optype == 1) && ((arg == GL_ALPHA) || (argRep == GL_NONE))))) {
-      _mesa_error(ctx, GL_INVALID_OPERATION, "C/AFragmentOpATI(sec_interp)");
-      return 0;
+   /* The ATI_fragment_shader spec says:
+    *
+    *        The error INVALID_OPERATION is generated by
+    *        ColorFragmentOp[1..3]ATI if <argN> is SECONDARY_INTERPOLATOR_ATI
+    *        and <argNRep> is ALPHA, or by AlphaFragmentOp[1..3]ATI if <argN>
+    *        is SECONDARY_INTERPOLATOR_ATI and <argNRep> is ALPHA or NONE, ...
+    */
+   if (arg == GL_SECONDARY_INTERPOLATOR_ATI) {
+      if (optype == ATI_FRAGMENT_SHADER_COLOR_OP && argRep == GL_ALPHA) {
+         _mesa_error(ctx, GL_INVALID_OPERATION, "CFragmentOpATI(sec_interp)");
+         return 0;
+      } else if (optype == ATI_FRAGMENT_SHADER_ALPHA_OP &&
+                 (argRep == GL_ALPHA || argRep == GL_NONE)) {
+         _mesa_error(ctx, GL_INVALID_OPERATION, "AFragmentOpATI(sec_interp)");
+         return 0;
+      }
    }
    if ((curProg->cur_pass == 1) &&
       ((arg == GL_PRIMARY_COLOR_ARB) || (arg == GL_SECONDARY_INTERPOLATOR_ATI))) {
@@ -644,10 +651,17 @@ _mesa_FragmentOpXATI(GLint optype, GLuint arg_count, GLenum op, GLuint dst,
 	 return;
       }
    }
-   if ((op == GL_DOT4_ATI) &&
-      (((arg1 == GL_SECONDARY_INTERPOLATOR_ATI) && ((arg1Rep == GL_ALPHA) || (arg1Rep == GL_NONE))) ||
-      (((arg2 == GL_SECONDARY_INTERPOLATOR_ATI) && ((arg2Rep == GL_ALPHA) || (arg2Rep == GL_NONE)))))) {
-      _mesa_error(ctx, GL_INVALID_OPERATION, "C/AFragmentOpATI(sec_interp)");
+   /* The ATI_fragment_shader spec says:
+    *
+    *        The error INVALID_OPERATION is generated by... ColorFragmentOp2ATI
+    *        if <op> is DOT4_ATI and <argN> is SECONDARY_INTERPOLATOR_ATI and
+    *        <argNRep> is ALPHA or NONE.
+    */
+   if (optype == ATI_FRAGMENT_SHADER_COLOR_OP && op == GL_DOT4_ATI &&
+       ((arg1 == GL_SECONDARY_INTERPOLATOR_ATI && (arg1Rep == GL_ALPHA || arg1Rep == GL_NONE)) ||
+       (arg2 == GL_SECONDARY_INTERPOLATOR_ATI && (arg2Rep == GL_ALPHA || arg2Rep == GL_NONE)))) {
+      _mesa_error(ctx, GL_INVALID_OPERATION, "C/AFragmentOpATI(sec_interpDOT4)");
+      return;
    }
 
    if (!check_arith_arg(curProg, optype, arg1, arg1Rep)) {
-- 
2.15.0.rc0