v3d: Do bool-to-cond for discard_if as well.

Turns this minimal conditional discard (glsl-fs-discard-01.shader_test):

0x3de0b086c5fe9000 fcmp.pushn  -, r1, r5; mov  r2, 0
0x3dec3086bbfc001f nop                  ; mov.ifa  r2, -1
0x3c047186bbe80000 nop                  ; mov.pushz  -, r2
0x3dea3186ba837000 setmsf.ifna  -, 0    ; nop

into:

0x3c00b186c582a000 fcmp.pushn  -, r2, r5; nop
0x3de83186ba837000 setmsf.ifa  -, 0     ; nop

total instructions in shared programs: 6229820 -> 6226247 (-0.06%)

diff --git a/src/broadcom/compiler/nir_to_vir.c b/src/broadcom/compiler/nir_to_vir.c
index dbd612f6682b2b024975539a2367bec87ce1b976..c0a606d8ef5f6df9b17ff6e381a1677a5390a65f 100644 (file)
--- a/src/broadcom/compiler/nir_to_vir.c
+++ b/src/broadcom/compiler/nir_to_vir.c
@@ -1897,26 +1897,22 @@ ntq_emit_intrinsic(struct v3d_compile *c, nir_intrinsic_instr *instr)
                 break;
 
         case nir_intrinsic_discard_if: {
-                /* true (~0) if we're discarding */
-                struct qreg cond = ntq_get_src(c, instr->src[0], 0);
+                enum v3d_qpu_cond cond = ntq_emit_bool_to_cond(c, instr->src[0]);
 
                 if (c->execute.file != QFILE_NULL) {
-                        /* execute == 0 means the channel is active.  Invert
-                         * the condition so that we can use zero as "executing
-                         * and discarding."
-                         */
-                        vir_PF(c, vir_OR(c, c->execute, vir_NOT(c, cond)),
-                               V3D_QPU_PF_PUSHZ);
-                        vir_set_cond(vir_SETMSF_dest(c, vir_nop_reg(),
-                                                     vir_uniform_ui(c, 0)),
-                                     V3D_QPU_COND_IFA);
-                } else {
-                        vir_PF(c, cond, V3D_QPU_PF_PUSHZ);
-                        vir_set_cond(vir_SETMSF_dest(c, vir_nop_reg(),
-                                                     vir_uniform_ui(c, 0)),
-                                     V3D_QPU_COND_IFNA);
+                        struct qinst *exec_flag = vir_MOV_dest(c, vir_nop_reg(),
+                                                               c->execute);
+                        if (cond == V3D_QPU_COND_IFA) {
+                                vir_set_uf(exec_flag, V3D_QPU_UF_ANDZ);
+                        } else {
+                                vir_set_uf(exec_flag, V3D_QPU_UF_NORNZ);
+                                cond = V3D_QPU_COND_IFA;
+                        }
                 }
 
+                vir_set_cond(vir_SETMSF_dest(c, vir_nop_reg(),
+                                             vir_uniform_ui(c, 0)), cond);
+
                 break;
         }