[PATCH] mesa: Fix bug in handling of read channel masks get_src_ar=

[Eric Anholt]

g_mask.

Fixes piglit glsl-fs-add-masked, and my GLSL demo.
---
 src/mesa/program/prog_optimize.c |   14 ++++----------
 1 files changed, 4 insertions(+), 10 deletions(-)

diff --git a/src/mesa/program/prog_optimize.c b/src/mesa/program/prog_optim=
ize.c
index 9119b10..c853330 100644
--- a/src/mesa/program/prog_optimize.c
+++ b/src/mesa/program/prog_optimize.c
@@ -51,12 +51,11 @@ static const int expand_one[5] =3D {0,1,3,7,15};
 static GLuint
 get_src_arg_mask(const struct prog_instruction *inst, int arg, int dst_mas=
k)
 {
-   int read_mask, channel_mask, read_count;
+   int read_mask, channel_mask;
    int comp;

    /* Form the dst register, find the written channels */
    if (inst->CondUpdate) {
-      read_count =3D 4;
       channel_mask =3D WRITEMASK_XYZW;
    }
    else {
@@ -67,8 +66,7 @@ get_src_arg_mask(const struct prog_instruction *inst, int=
 arg, int dst_mask)
       case OPCODE_MAD:
       case OPCODE_MUL:
       case OPCODE_SUB:
-         read_count =3D bit_count[inst->DstReg.WriteMask & dst_mask];
-         channel_mask =3D expand_one[read_count];
+         channel_mask =3D inst->DstReg.WriteMask & dst_mask;
          break;
       case OPCODE_RCP:
       case OPCODE_SIN:
@@ -76,20 +74,16 @@ get_src_arg_mask(const struct prog_instruction *inst, i=
nt arg, int dst_mask)
       case OPCODE_RSQ:
       case OPCODE_POW:
       case OPCODE_EX2:
-         read_count =3D 1;
          channel_mask =3D WRITEMASK_X;
          break;
       case OPCODE_DP2:
-         read_count =3D 2;
          channel_mask =3D WRITEMASK_XY;
          break;
       case OPCODE_DP3:
       case OPCODE_XPD:
-         read_count =3D 3;
          channel_mask =3D WRITEMASK_XYZ;
          break;
       default:
-         read_count =3D 4;
          channel_mask =3D WRITEMASK_XYZW;
          break;
       }
@@ -99,9 +93,9 @@ get_src_arg_mask(const struct prog_instruction *inst, int=
 arg, int dst_mask)
     * components are actually read
     */
    read_mask =3D 0;
-   for (comp =3D 0; comp < read_count; ++comp) {
+   for (comp =3D 0; comp < 4; ++comp) {
       const int coord =3D GET_SWZ(inst->SrcReg[arg].Swizzle, comp);
-      if (coord <=3D SWIZZLE_W)
+      if (channel_mask & (1 << comp) && coord <=3D SWIZZLE_W)
          read_mask |=3D 1 << coord;
    }

--
1.7.1