[Mesa-dev] [PATCH] i965: in MAD->MUL, switch last argument to be immediate

[Tapani Pälli]

Commit bb33a31 introduced MAD->MUL optimization which did not
take account case where one of the remaining sources is immediate
and did not report progress. Patch changes last one of the sources
to be immediate and adds progress reporting. If both are, this is
taken care of by the same opt_algebraic pass on later run.

Signed-off-by: Tapani Pälli <tapani.palli at intel.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=89569
---
 src/mesa/drivers/dri/i965/brw_fs.cpp | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/src/mesa/drivers/dri/i965/brw_fs.cpp b/src/mesa/drivers/dri/i965/brw_fs.cpp
index 8702ea8..710a7e6 100644
--- a/src/mesa/drivers/dri/i965/brw_fs.cpp
+++ b/src/mesa/drivers/dri/i965/brw_fs.cpp
@@ -2490,7 +2490,14 @@ fs_visitor::opt_algebraic()
          } else if (inst->src[0].is_zero()) {
             inst->opcode = BRW_OPCODE_MUL;
             inst->src[0] = inst->src[2];
+            /* Last one needs to be immediate. */
+            if (inst->src[0].file == IMM) {
+               inst->src[2] = inst->src[1];
+               inst->src[1] = inst->src[0];
+               inst->src[0] = inst->src[2];
+            }
             inst->src[2] = reg_undef;
+            progress = true;
          } else if (inst->src[1].is_one()) {
             inst->opcode = BRW_OPCODE_ADD;
             inst->src[1] = inst->src[2];
-- 
2.1.0