intel/fs: Don't lower integer multiplies that don't need lowering

v2: Move the check to fs_visitor::lower_integer_multiplication.
Previously the cases where lowering was skipped, the original
instruction was removed by fs_visitor::lower_integer_multiplication.

Reviewed-by: Caio Marcelo de Oliveira Filho <caio.oliveira@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/merge_requests/767>

diff --git a/src/intel/compiler/brw_fs.cpp b/src/intel/compiler/brw_fs.cpp
index d9afe425e3192b07dcf3aec2c5be2001fe3c341b..b09203cc87b1885633aa2ed6234cadf7ad2a7496 100644 (file)
--- a/src/intel/compiler/brw_fs.cpp
+++ b/src/intel/compiler/brw_fs.cpp
@@ -4107,6 +4107,17 @@ fs_visitor::lower_integer_multiplication()
 
    foreach_block_and_inst_safe(block, fs_inst, inst, cfg) {
       if (inst->opcode == BRW_OPCODE_MUL) {
+         /* If the instruction is already in a form that does not need lowering,
+          * return early.
+          */
+         if (devinfo->gen >= 7) {
+            if (type_sz(inst->src[1].type) < 4 && type_sz(inst->src[0].type) <= 4)
+               continue;
+         } else {
+            if (type_sz(inst->src[0].type) < 4 && type_sz(inst->src[1].type) <= 4)
+               continue;
+         }
+
          if ((inst->dst.type == BRW_REGISTER_TYPE_Q ||
               inst->dst.type == BRW_REGISTER_TYPE_UQ) &&
              (inst->src[0].type == BRW_REGISTER_TYPE_Q ||