[Mesa-dev] [PATCH 3/3] tgsi/scan: set which color components are read by a fragment shader

[Marek Olšák]

From: Marek Olšák <marek.olsak at amd.com>

This will be used by radeonsi.
---
 src/gallium/auxiliary/tgsi/tgsi_scan.c | 30 ++++++++++++++++++++++--------
 src/gallium/auxiliary/tgsi/tgsi_scan.h |  1 +
 2 files changed, 23 insertions(+), 8 deletions(-)

diff --git a/src/gallium/auxiliary/tgsi/tgsi_scan.c b/src/gallium/auxiliary/tgsi/tgsi_scan.c
index e3a6fb0..6ea32ee 100644
--- a/src/gallium/auxiliary/tgsi/tgsi_scan.c
+++ b/src/gallium/auxiliary/tgsi/tgsi_scan.c
@@ -187,14 +187,28 @@ tgsi_scan_shader(const struct tgsi_token *tokens,
                   }
 
                   if (procType == TGSI_PROCESSOR_FRAGMENT &&
-		      !src->Register.Indirect &&
-		      info->input_semantic_name[src->Register.Index] ==
-		      TGSI_SEMANTIC_POSITION &&
-                      (src->Register.SwizzleX == TGSI_SWIZZLE_Z ||
-                       src->Register.SwizzleY == TGSI_SWIZZLE_Z ||
-                       src->Register.SwizzleZ == TGSI_SWIZZLE_Z ||
-                       src->Register.SwizzleW == TGSI_SWIZZLE_Z)) {
-                     info->reads_z = TRUE;
+                      !src->Register.Indirect) {
+                     unsigned name =
+                        info->input_semantic_name[src->Register.Index];
+                     unsigned index =
+                        info->input_semantic_index[src->Register.Index];
+
+                     if (name == TGSI_SEMANTIC_POSITION &&
+                         (src->Register.SwizzleX == TGSI_SWIZZLE_Z ||
+                          src->Register.SwizzleY == TGSI_SWIZZLE_Z ||
+                          src->Register.SwizzleZ == TGSI_SWIZZLE_Z ||
+                          src->Register.SwizzleW == TGSI_SWIZZLE_Z))
+                        info->reads_z = TRUE;
+
+                     if (name == TGSI_SEMANTIC_COLOR) {
+                        unsigned mask =
+                              (1 << src->Register.SwizzleX) |
+                              (1 << src->Register.SwizzleY) |
+                              (1 << src->Register.SwizzleZ) |
+                              (1 << src->Register.SwizzleW);
+
+                        info->colors_read |= mask << (index * 4);
+                     }
                   }
                }
 
diff --git a/src/gallium/auxiliary/tgsi/tgsi_scan.h b/src/gallium/auxiliary/tgsi/tgsi_scan.h
index a3e4378..b0b423a 100644
--- a/src/gallium/auxiliary/tgsi/tgsi_scan.h
+++ b/src/gallium/auxiliary/tgsi/tgsi_scan.h
@@ -77,6 +77,7 @@ struct tgsi_shader_info
 
    uint opcode_count[TGSI_OPCODE_LAST];  /**< opcode histogram */
 
+   ubyte colors_read; /**< which color components are read by the FS */
    ubyte colors_written;
    boolean reads_position; /**< does fragment shader read position? */
    boolean reads_z; /**< does fragment shader read depth? */
-- 
2.1.4