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authorBrian Paul <[email protected]>2010-07-29 08:23:59 -0600
committerBrian Paul <[email protected]>2010-07-29 08:23:59 -0600
commitb4ad7c28430e4084d843cd99cf68209e95363963 (patch)
tree2fae93b056cd18a9ae00c252da25525eaf061f90
parent275bae875da228b82a6d61fdab5dbe487f557580 (diff)
mesa: implement RCC opcode
-rw-r--r--src/mesa/program/prog_execute.c54
1 files changed, 54 insertions, 0 deletions
diff --git a/src/mesa/program/prog_execute.c b/src/mesa/program/prog_execute.c
index f85c6513f31..6c50f409d29 100644
--- a/src/mesa/program/prog_execute.c
+++ b/src/mesa/program/prog_execute.c
@@ -81,6 +81,22 @@ static const GLfloat ZeroVec[4] = { 0.0F, 0.0F, 0.0F, 0.0F };
/**
+ * Return TRUE for +0 and other positive values, FALSE otherwise.
+ * Used for RCC opcode.
+ */
+static INLINE GLboolean
+positive(float x)
+{
+ fi_type fi;
+ fi.f = x;
+ if (fi.i & 0x80000000)
+ return GL_FALSE;
+ return GL_TRUE;
+}
+
+
+
+/**
* Return a pointer to the 4-element float vector specified by the given
* source register.
*/
@@ -1340,6 +1356,44 @@ _mesa_execute_program(GLcontext * ctx,
store_vector4(inst, machine, result);
}
break;
+ case OPCODE_RCC: /* clamped riciprocal */
+ {
+ const float largest = 1.884467e+19, smallest = 5.42101e-20;
+ GLfloat a[4], r, result[4];
+ fetch_vector1(&inst->SrcReg[0], machine, a);
+ if (DEBUG_PROG) {
+ if (a[0] == 0)
+ printf("RCC(0)\n");
+ else if (IS_INF_OR_NAN(a[0]))
+ printf("RCC(inf)\n");
+ }
+ if (a[0] == 1.0F) {
+ r = 1.0F;
+ }
+ else {
+ r = 1.0F / a[0];
+ }
+ if (positive(r)) {
+ if (r > largest) {
+ r = largest;
+ }
+ else if (r < smallest) {
+ r = smallest;
+ }
+ }
+ else {
+ if (r < -largest) {
+ r = -largest;
+ }
+ else if (r > -smallest) {
+ r = -smallest;
+ }
+ }
+ result[0] = result[1] = result[2] = result[3] = r;
+ store_vector4(inst, machine, result);
+ }
+ break;
+
case OPCODE_RCP:
{
GLfloat a[4], result[4];