emit_bool_to_cond_code() takes separate paths for ir_expressions and. If the argument to emit_bool_to_cond_code() is an ir_expression, we loop over the operands, calling accept() on each of them, which generates assembly code to compute that subexpression. We then emit one or two final instruction that perform the top-level operation on those operands.
If it's not an expression (say, a boolean-valued variable), we simply call accept() on the whole value. In commit 80ecb8f1 (i965/fs: Avoid generating extra AND instructions on bool logic ops), Eric made logic operations jump out of the expression path to the non-expression path. Unfortunately, this meant that we would first accept() the two operands, skip generating any code that used them, then accept() the whole expression, generating code for the operands a second time. Dead code elimination would always remove the first set of redundant operand assembly, since nothing actually used them. But we shouldn't generate it in the first place. Signed-off-by: Kenneth Graunke <[email protected]> Cc: Matt Turner <[email protected]> Cc: Eric Anholt <[email protected]> --- src/mesa/drivers/dri/i965/brw_fs_visitor.cpp | 11 ++++------- 1 file changed, 4 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 946525b..bd94ea3 100644 --- a/src/mesa/drivers/dri/i965/brw_fs_visitor.cpp +++ b/src/mesa/drivers/dri/i965/brw_fs_visitor.cpp @@ -1724,7 +1724,10 @@ fs_visitor::emit_bool_to_cond_code(ir_rvalue *ir) { ir_expression *expr = ir->as_expression(); - if (expr) { + if (expr && + expr->operation != ir_binop_logic_and && + expr->operation != ir_binop_logic_or && + expr->operation != ir_binop_logic_xor) { fs_reg op[2]; fs_inst *inst; @@ -1742,11 +1745,6 @@ fs_visitor::emit_bool_to_cond_code(ir_rvalue *ir) inst->conditional_mod = BRW_CONDITIONAL_Z; break; - case ir_binop_logic_xor: - case ir_binop_logic_or: - case ir_binop_logic_and: - goto out; - case ir_unop_f2b: if (brw->gen >= 6) { emit(CMP(reg_null_d, op[0], fs_reg(0.0f), BRW_CONDITIONAL_NZ)); @@ -1788,7 +1786,6 @@ fs_visitor::emit_bool_to_cond_code(ir_rvalue *ir) return; } -out: ir->accept(this); fs_inst *inst = emit(AND(reg_null_d, this->result, fs_reg(1))); -- 1.8.3.4 _______________________________________________ mesa-dev mailing list [email protected] http://lists.freedesktop.org/mailman/listinfo/mesa-dev
