mesa: rework GLSL array code generation

We now express arrays in terms of indirect addressing.  For example:
  dst = a[i];
becomes:
  MOV dst, TEMP[1 + TEMP[2].y];
At instruction-emit time indirect addressing is converted into ARL/
ADDR-relative form:
  ARL ADDR.x, TEMP[2].y;
  MOV dst, TEMP[1 + ADDR.x];
This fixes a number of array-related issues.  Arrays of arrays and complex
array/struct nesting works now.
There may be some regressions, but more work is coming.

(cherry picked from commit ae0ff8097b85d3537a7be1674d55a44a9bd6018e)

1 files changed, 51 insertions, 6 deletions

diff --git a/src/mesa/shader/slang/slang_ir.h b/src/mesa/shader/slang/slang_ir.h
index 4cd81f0fc7..cc784d431b 100644
--- a/src/mesa/shader/slang/slang_ir.h
+++ b/src/mesa/shader/slang/slang_ir.h
@@ -137,24 +137,53 @@ typedef enum
 
 
 /**
- * Describes where data storage is allocated.
+ * Describes where data/variables are stored in the various register files.
+ *
+ * In the simple case, the File, Index and Size fields indicate where
+ * a variable is stored.  For example, a vec3 variable may be stored
+ * as (File=PROGRAM_TEMPORARY, Index=6, Size=3).  Or, File[Index].
+ * Or, a program input like color may be stored as
+ * (File=PROGRAM_INPUT,Index=3,Size=4);
+ *
+ * For single-float values, the Swizzle field indicates which component
+ * of the vector contains the float.
+ *
+ * If IsIndirect is set, the storage is accessed through an indirect
+ * register lookup.  The value in question will be located at:
+ *   File[Index + IndirectFile[IndirectIndex]]
+ *
+ * This is primary used for indexing arrays.  For example, consider this
+ * GLSL code:
+ *   uniform int i;
+ *   float a[10];
+ *   float x = a[i];
+ *
+ * here, storage for a[i] would be described by (File=PROGRAM_TEMPORAY,
+ * Index=aPos, IndirectFile=PROGRAM_UNIFORM, IndirectIndex=iPos), which
+ * would mean TEMP[aPos + UNIFORM[iPos]]
  */
-struct _slang_ir_storage
+struct slang_ir_storage_
 {
    enum register_file File;  /**< PROGRAM_TEMPORARY, PROGRAM_INPUT, etc */
    GLint Index;  /**< -1 means unallocated */
    GLint Size;  /**< number of floats */
-   GLuint Swizzle;
+   GLuint Swizzle; /**< Swizzle AND writemask info */
    GLint RefCount; /**< Used during IR tree delete */
-   GLboolean RelAddr;
+
+   GLboolean RelAddr; /* we'll remove this eventually */
+
+   GLboolean IsIndirect;
+   enum register_file IndirectFile;
+   GLint IndirectIndex;
+   GLuint IndirectSwizzle;
 
    /** If Parent is non-null, Index is relative to parent.
     * The other fields are ignored.
     */
-   struct _slang_ir_storage *Parent;
+   struct slang_ir_storage_ *Parent;
 };
 
-typedef struct _slang_ir_storage slang_ir_storage;
+typedef struct slang_ir_storage_ slang_ir_storage;
 
 
 /**
@@ -196,6 +225,11 @@ extern const slang_ir_info *
 _slang_ir_info(slang_ir_opcode opcode);
 
 
+extern void
+_slang_init_ir_storage(slang_ir_storage *st,
+                       enum register_file file, GLint index, GLint size,
+                       GLuint swizzle);
+
 extern slang_ir_storage *
 _slang_new_ir_storage(enum register_file file, GLint index, GLint size);
 
@@ -209,6 +243,17 @@ _slang_new_ir_storage_relative(GLint index, GLint size,
                                slang_ir_storage *parent);
 
 
+extern slang_ir_storage *
+_slang_new_ir_storage_indirect(enum register_file file,
+                               GLint index,
+                               GLint size,
+                               enum register_file indirectFile,
+                               GLint indirectIndex,
+                               GLuint indirectSwizzle);
+
+extern void
+_slang_copy_ir_storage(slang_ir_storage *dst, const slang_ir_storage *src);
+
 
 extern void
 _slang_free_ir_tree(slang_ir_node *n);