[Mesa-dev] [PATCH v2] Gallium/tgsi: Correct signedness of return value of bit operations

[Gert Wollny]

From: Gert Wollny <gert.wollny at collabora.com>

The GLSL operations findLSB, findMSB, and countBits always return
a signed integer type. Let TGSI reflect this.

v2: Properly set values in infer_(src|dst)_type   (Thanks Roland
    Schneideregger for pointing out problems with my 1st approach)

Signed-off-by: Gert Wollny <gert.wollny at collabora.com>
---
 src/gallium/auxiliary/tgsi/tgsi_info.c | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/src/gallium/auxiliary/tgsi/tgsi_info.c b/src/gallium/auxiliary/tgsi/tgsi_info.c
index bbe1a21e43..ff58b4c22e 100644
--- a/src/gallium/auxiliary/tgsi/tgsi_info.c
+++ b/src/gallium/auxiliary/tgsi/tgsi_info.c
@@ -150,9 +150,6 @@ tgsi_opcode_infer_type(enum tgsi_opcode opcode)
    case TGSI_OPCODE_UBFE:
    case TGSI_OPCODE_BFI:
    case TGSI_OPCODE_BREV:
-   case TGSI_OPCODE_POPC:
-   case TGSI_OPCODE_LSB:
-   case TGSI_OPCODE_UMSB:
    case TGSI_OPCODE_IMG2HND:
    case TGSI_OPCODE_SAMP2HND:
       return TGSI_TYPE_UNSIGNED;
@@ -269,6 +266,7 @@ tgsi_opcode_infer_src_type(enum tgsi_opcode opcode, uint src_idx)
    case TGSI_OPCODE_UP2H:
    case TGSI_OPCODE_U2I64:
    case TGSI_OPCODE_MEMBAR:
+   case TGSI_OPCODE_UMSB:
       return TGSI_TYPE_UNSIGNED;
    case TGSI_OPCODE_IMUL_HI:
    case TGSI_OPCODE_I2F:
@@ -324,5 +322,12 @@ tgsi_opcode_infer_dst_type(enum tgsi_opcode opcode, uint dst_idx)
    if (dst_idx == 1 && opcode == TGSI_OPCODE_DFRACEXP)
       return TGSI_TYPE_SIGNED;
 
-   return tgsi_opcode_infer_type(opcode);
+   switch (opcode) {
+   case TGSI_OPCODE_LSB:
+   case TGSI_OPCODE_POPC:
+   case TGSI_OPCODE_UMSB:
+      return TGSI_TYPE_SIGNED;
+   default:
+      return tgsi_opcode_infer_type(opcode);
+   }
 }
-- 
2.16.4