i965: Use greater-equal cmod to implement maximum.

The docs specifically call out SEL with .l and .ge as the
implementations of MIN and MAX respectively. Among other things, SEL
with these conditional mods are commutative.

Reviewed-by: Ian Romanick <[email protected]>

4 files changed, 10 insertions, 7 deletions

diff --git a/src/mesa/drivers/dri/i965/brw_fs_visitor.cpp b/src/mesa/drivers/dri/i965/brw_fs_visitor.cpp
index 74860711abd..4b48f2db0f2 100644
--- a/src/mesa/drivers/dri/i965/brw_fs_visitor.cpp
+++ b/src/mesa/drivers/dri/i965/brw_fs_visitor.cpp
@@ -321,6 +321,9 @@ void
 fs_visitor::emit_minmax(enum brw_conditional_mod conditionalmod, const fs_reg &dst,
                         const fs_reg &src0, const fs_reg &src1)
 {
+   assert(conditionalmod == BRW_CONDITIONAL_GE ||
+          conditionalmod == BRW_CONDITIONAL_L);
+
    fs_inst *inst;
 
    if (brw->gen >= 6) {
@@ -1956,7 +1959,7 @@ fs_visitor::rescale_texcoord(fs_reg coordinate, int coord_components,
 	    chan = offset(chan, i);
 
 	    inst = emit(BRW_OPCODE_SEL, chan, chan, fs_reg(0.0f));
-	    inst->conditional_mod = BRW_CONDITIONAL_G;
+	    inst->conditional_mod = BRW_CONDITIONAL_GE;
 
 	    /* Our parameter comes in as 1.0/width or 1.0/height,
 	     * because that's what people normally want for doing
diff --git a/src/mesa/drivers/dri/i965/brw_vec4_visitor.cpp b/src/mesa/drivers/dri/i965/brw_vec4_visitor.cpp
index 6154e43c1a4..be071d74baa 100644
--- a/src/mesa/drivers/dri/i965/brw_vec4_visitor.cpp
+++ b/src/mesa/drivers/dri/i965/brw_vec4_visitor.cpp
@@ -517,7 +517,7 @@ vec4_visitor::emit_unpack_snorm_4x8(const dst_reg &dst, src_reg src0)
    emit(MUL(scaled, src_reg(f), src_reg(1.0f / 127.0f)));
 
    dst_reg max(this, glsl_type::vec4_type);
-   emit_minmax(BRW_CONDITIONAL_G, max, src_reg(scaled), src_reg(-1.0f));
+   emit_minmax(BRW_CONDITIONAL_GE, max, src_reg(scaled), src_reg(-1.0f));
    emit_minmax(BRW_CONDITIONAL_L, dst, src_reg(max), src_reg(1.0f));
 }
 
@@ -545,7 +545,7 @@ void
 vec4_visitor::emit_pack_snorm_4x8(const dst_reg &dst, const src_reg &src0)
 {
    dst_reg max(this, glsl_type::vec4_type);
-   emit_minmax(BRW_CONDITIONAL_G, max, src0, src_reg(-1.0f));
+   emit_minmax(BRW_CONDITIONAL_GE, max, src0, src_reg(-1.0f));
 
    dst_reg min(this, glsl_type::vec4_type);
    emit_minmax(BRW_CONDITIONAL_L, min, src_reg(max), src_reg(1.0f));
@@ -1683,7 +1683,7 @@ vec4_visitor::visit(ir_expression *ir)
       emit_minmax(BRW_CONDITIONAL_L, result_dst, op[0], op[1]);
       break;
    case ir_binop_max:
-      emit_minmax(BRW_CONDITIONAL_G, result_dst, op[0], op[1]);
+      emit_minmax(BRW_CONDITIONAL_GE, result_dst, op[0], op[1]);
       break;
 
    case ir_binop_pow:
diff --git a/src/mesa/drivers/dri/i965/brw_vec4_vp.cpp b/src/mesa/drivers/dri/i965/brw_vec4_vp.cpp
index a5a5e7bfd5b..ba3264dce6f 100644
--- a/src/mesa/drivers/dri/i965/brw_vec4_vp.cpp
+++ b/src/mesa/drivers/dri/i965/brw_vec4_vp.cpp
@@ -226,7 +226,7 @@ vec4_vs_visitor::emit_program_code()
                /* if (tmp.y < 0) tmp.y = 0; */
                src_reg tmp_y = swizzle(src[0], BRW_SWIZZLE_YYYY);
                result.writemask = WRITEMASK_Z;
-               emit_minmax(BRW_CONDITIONAL_G, result, tmp_y, src_reg(0.0f));
+               emit_minmax(BRW_CONDITIONAL_GE, result, tmp_y, src_reg(0.0f));
 
                src_reg clamped_y(result);
                clamped_y.swizzle = BRW_SWIZZLE_ZZZZ;
@@ -313,7 +313,7 @@ vec4_vs_visitor::emit_program_code()
       }
 
       case OPCODE_MAX:
-         emit_minmax(BRW_CONDITIONAL_G, dst, src[0], src[1]);
+         emit_minmax(BRW_CONDITIONAL_GE, dst, src[0], src[1]);
          break;
 
       case OPCODE_MIN:
diff --git a/src/mesa/drivers/dri/i965/brw_vec4_vs_visitor.cpp b/src/mesa/drivers/dri/i965/brw_vec4_vs_visitor.cpp
index 129c2db638b..4baf73ebde1 100644
--- a/src/mesa/drivers/dri/i965/brw_vec4_vs_visitor.cpp
+++ b/src/mesa/drivers/dri/i965/brw_vec4_vs_visitor.cpp
@@ -97,7 +97,7 @@ vec4_vs_visitor::emit_prolog()
                dst.type = brw_type_for_base_type(glsl_type::vec4_type);
                emit(MOV(dst, src_reg(reg_d)));
                emit(MUL(dst, src_reg(dst), src_reg(es3_normalize_factor)));
-               emit_minmax(BRW_CONDITIONAL_G, dst, src_reg(dst), src_reg(-1.0f));
+               emit_minmax(BRW_CONDITIONAL_GE, dst, src_reg(dst), src_reg(-1.0f));
             } else {
                /* The following equations are from the OpenGL 3.2 specification:
                 *