mesa: use correct tex unit lod bias for TXB instruction

(cherry picked from master, commit 1ab225017ed1ea8bd9e266d10ee56ab914bb28c1)

1 files changed, 2 insertions, 2 deletions

diff --git a/src/mesa/shader/prog_execute.c b/src/mesa/shader/prog_execute.c
index a93733c0852..6a79cf40372 100644
--- a/src/mesa/shader/prog_execute.c
+++ b/src/mesa/shader/prog_execute.c
@@ -1577,8 +1577,8 @@ _mesa_execute_program(GLcontext * ctx,
       case OPCODE_TXB:         /* GL_ARB_fragment_program only */
          /* Texel lookup with LOD bias */
          {
-            const struct gl_texture_unit *texUnit
-               = &ctx->Texture.Unit[inst->TexSrcUnit];
+            const GLuint unit = machine->Samplers[inst->TexSrcUnit];
+            const struct gl_texture_unit *texUnit = &ctx->Texture.Unit[unit];
             GLfloat texcoord[4], color[4], lodBias;
 
             fetch_vector4(&inst->SrcReg[0], machine, texcoord);