From: Eric Anholt <eric@anholt.net>
Date: Sat, 27 Mar 2010 20:01:51 +0000 (-0700)
Subject: Add sqrt() builtin as an IR operation.
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=44d68fd06ff8b53fc70a9a07c897dda9b3457ef8;p=mesa.git

Add sqrt() builtin as an IR operation.

Following a discussion in #dri-devel, I think this makes more sense
than implementing it as RSQ RCP CMP as Mesa did.  The i965 has a
hardware sqrt that should work, and AMD is suppposed to be able to
implement it as RSQ RCP with an alternate floating point mode so that
the 0.0 case is handled like we want.
---

diff --git a/builtin_function.cpp b/builtin_function.cpp
index ec1b54a2dd5..9d231e872b6 100644
--- a/builtin_function.cpp
+++ b/builtin_function.cpp
@@ -84,6 +84,14 @@ generate_rsq(exec_list *instructions,
    generate_unop(instructions, declarations, type, ir_unop_rsq);
 }
 
+static void
+generate_sqrt(exec_list *instructions,
+	       ir_variable **declarations,
+	       const glsl_type *type)
+{
+   generate_unop(instructions, declarations, type, ir_unop_sqrt);
+}
+
 static void
 generate_abs(exec_list *instructions,
 	     ir_variable **declarations,
@@ -227,7 +235,7 @@ generate_110_functions(glsl_symbol_table *symtab, exec_list *instructions)
    make_gentype_function(symtab, instructions, "log", 1, generate_log);
    /* FINISHME: exp2() */
    /* FINISHME: log2() */
-   /* FINISHME: sqrt() */
+   make_gentype_function(symtab, instructions, "sqrt", 1, generate_sqrt);
    make_gentype_function(symtab, instructions, "inversesqrt", 1, generate_rsq);
    make_gentype_function(symtab, instructions, "abs", 1, generate_abs);
    /* FINISHME: sign() */
diff --git a/ir.h b/ir.h
index bad5111b5a8..45905289485 100644
--- a/ir.h
+++ b/ir.h
@@ -225,6 +225,7 @@ enum ir_expression_operation {
    ir_unop_abs,
    ir_unop_rcp,
    ir_unop_rsq,
+   ir_unop_sqrt,
    ir_unop_exp,
    ir_unop_log,
    ir_unop_f2i,      /**< Float-to-integer conversion. */
diff --git a/ir_print_visitor.cpp b/ir_print_visitor.cpp
index ecfdb49c480..8b2080f7ec5 100644
--- a/ir_print_visitor.cpp
+++ b/ir_print_visitor.cpp
@@ -93,6 +93,7 @@ void ir_print_visitor::visit(ir_expression *ir)
       "abs",
       "rcp",
       "rsq",
+      "sqrt",
       "exp",
       "log",
       "f2i",