i965/fs: split out calculation of payload live ranges

We'll need this for the scheduler too, since it wants to know when the
live ranges of payload registers end in order to model them in our
register pressure calculations.

Reviewed-by: Jason Ekstrand <[email protected]>

2 files changed, 31 insertions, 22 deletions

diff --git a/src/mesa/drivers/dri/i965/brw_fs.h b/src/mesa/drivers/dri/i965/brw_fs.h
index d98769df4dc..8058b344b7a 100644
--- a/src/mesa/drivers/dri/i965/brw_fs.h
+++ b/src/mesa/drivers/dri/i965/brw_fs.h
@@ -145,6 +145,8 @@ public:
    void assign_vs_urb_setup();
    bool assign_regs(bool allow_spilling);
    void assign_regs_trivial();
+   void calculate_payload_ranges(int payload_node_count,
+                                 int *payload_last_use_ip);
    void setup_payload_interference(struct ra_graph *g, int payload_reg_count,
                                    int first_payload_node);
    int choose_spill_reg(struct ra_graph *g);
diff --git a/src/mesa/drivers/dri/i965/brw_fs_reg_allocate.cpp b/src/mesa/drivers/dri/i965/brw_fs_reg_allocate.cpp
index 36388fad98d..9251d9552a5 100644
--- a/src/mesa/drivers/dri/i965/brw_fs_reg_allocate.cpp
+++ b/src/mesa/drivers/dri/i965/brw_fs_reg_allocate.cpp
@@ -330,32 +330,12 @@ count_to_loop_end(const bblock_t *block)
    unreachable("not reached");
 }
 
-/**
- * Sets up interference between thread payload registers and the virtual GRFs
- * to be allocated for program temporaries.
- *
- * We want to be able to reallocate the payload for our virtual GRFs, notably
- * because the setup coefficients for a full set of 16 FS inputs takes up 8 of
- * our 128 registers.
- *
- * The layout of the payload registers is:
- *
- * 0..payload.num_regs-1: fixed function setup (including bary coordinates).
- * payload.num_regs..payload.num_regs+curb_read_lengh-1: uniform data
- * payload.num_regs+curb_read_lengh..first_non_payload_grf-1: setup coefficients.
- *
- * And we have payload_node_count nodes covering these registers in order
- * (note that in SIMD16, a node is two registers).
- */
-void
-fs_visitor::setup_payload_interference(struct ra_graph *g,
-                                       int payload_node_count,
-                                       int first_payload_node)
+void fs_visitor::calculate_payload_ranges(int payload_node_count,
+                                          int *payload_last_use_ip)
 {
    int loop_depth = 0;
    int loop_end_ip = 0;
 
-   int payload_last_use_ip[payload_node_count];
    for (int i = 0; i < payload_node_count; i++)
       payload_last_use_ip[i] = -1;
 
@@ -426,6 +406,33 @@ fs_visitor::setup_payload_interference(struct ra_graph *g,
 
       ip++;
    }
+}
+
+
+/**
+ * Sets up interference between thread payload registers and the virtual GRFs
+ * to be allocated for program temporaries.
+ *
+ * We want to be able to reallocate the payload for our virtual GRFs, notably
+ * because the setup coefficients for a full set of 16 FS inputs takes up 8 of
+ * our 128 registers.
+ *
+ * The layout of the payload registers is:
+ *
+ * 0..payload.num_regs-1: fixed function setup (including bary coordinates).
+ * payload.num_regs..payload.num_regs+curb_read_lengh-1: uniform data
+ * payload.num_regs+curb_read_lengh..first_non_payload_grf-1: setup coefficients.
+ *
+ * And we have payload_node_count nodes covering these registers in order
+ * (note that in SIMD16, a node is two registers).
+ */
+void
+fs_visitor::setup_payload_interference(struct ra_graph *g,
+                                       int payload_node_count,
+                                       int first_payload_node)
+{
+   int payload_last_use_ip[payload_node_count];
+   calculate_payload_ranges(payload_node_count, payload_last_use_ip);
 
    for (int i = 0; i < payload_node_count; i++) {
       if (payload_last_use_ip[i] == -1)