vc4: Split two notions of instructions having side effects.

Some ops can't be DCEd, while some of the ops that are just important due
to the args they have can be.

diff --git a/src/gallium/drivers/vc4/vc4_opt_cse.c b/src/gallium/drivers/vc4/vc4_opt_cse.c
index 2ca736fe4d5b7b30e9ec0ded260a192791aad4c9..aff777beb47a101e20520f614475384b44da4235 100644 (file)
--- a/src/gallium/drivers/vc4/vc4_opt_cse.c
+++ b/src/gallium/drivers/vc4/vc4_opt_cse.c
@@ -133,7 +133,8 @@ qir_opt_cse(struct vc4_compile *c)
         foreach_s(node, t, &c->instructions) {
                 struct qinst *inst = (struct qinst *)node;
 
-                if (qir_has_side_effects(c, inst)) {
+                if (qir_has_side_effects(c, inst) ||
+                    qir_has_side_effect_reads(c, inst)) {
                         if (inst->op == QOP_TLB_DISCARD_SETUP)
                                 last_sf = NULL;
                         continue;

diff --git a/src/gallium/drivers/vc4/vc4_opt_dead_code.c b/src/gallium/drivers/vc4/vc4_opt_dead_code.c
index 408bd4302b4072e6913bc17a968d656f8191adc8..f555fcb600e8b8ec6571b32289f5307b115e6463 100644 (file)
--- a/src/gallium/drivers/vc4/vc4_opt_dead_code.c
+++ b/src/gallium/drivers/vc4/vc4_opt_dead_code.c
@@ -64,7 +64,8 @@ qir_opt_dead_code(struct vc4_compile *c)
                 if (inst->dst.file == QFILE_TEMP &&
                     !used[inst->dst.index] &&
                     (!qir_has_side_effects(c, inst) ||
-                     inst->op == QOP_TEX_RESULT)) {
+                     inst->op == QOP_TEX_RESULT) &&
+                    !(qir_has_side_effect_reads(c, inst))) {
                         if (inst->op == QOP_TEX_RESULT) {
                                 dce_tex = true;
                                 c->num_texture_samples--;

diff --git a/src/gallium/drivers/vc4/vc4_opt_vpm_writes.c b/src/gallium/drivers/vc4/vc4_opt_vpm_writes.c
index 477d32605a408e7fe3d4637f89c54de2abd3d2e5..0269e32494a961b44066a684017e95276ae4e73e 100644 (file)
--- a/src/gallium/drivers/vc4/vc4_opt_vpm_writes.c
+++ b/src/gallium/drivers/vc4/vc4_opt_vpm_writes.c
@@ -82,8 +82,10 @@ qir_opt_vpm_writes(struct vc4_compile *c)
                 if (qir_depends_on_flags(inst))
                         continue;
 
-                if (qir_has_side_effects(c, inst))
+                if (qir_has_side_effects(c, inst) ||
+                    qir_has_side_effect_reads(c, inst)) {
                         continue;
+                }
 
                 /* A QOP_TEX_RESULT destination is r4, so we can't move
                  * accesses to it past another QOP_TEX_RESULT which would

diff --git a/src/gallium/drivers/vc4/vc4_qir.c b/src/gallium/drivers/vc4/vc4_qir.c
index 4f73932e233f8d08dd31314a30ed3888ae4423be..40356c99ff317e30100ef8432cf40d6863e51dd8 100644 (file)
--- a/src/gallium/drivers/vc4/vc4_qir.c
+++ b/src/gallium/drivers/vc4/vc4_qir.c
@@ -140,6 +140,12 @@ qir_get_op_nsrc(enum qop qop)
  */
 bool
 qir_has_side_effects(struct vc4_compile *c, struct qinst *inst)
+{
+        return qir_op_info[inst->op].has_side_effects;
+}
+
+bool
+qir_has_side_effect_reads(struct vc4_compile *c, struct qinst *inst)
 {
         /* We can dead-code eliminate varyings, because we only tell the VS
          * about the live ones at the end.  But we have to preserve the
@@ -159,7 +165,7 @@ qir_has_side_effects(struct vc4_compile *c, struct qinst *inst)
         if (inst->dst.file == QFILE_VPM)
                 return true;
 
-        return qir_op_info[inst->op].has_side_effects;
+        return false;
 }
 
 bool

diff --git a/src/gallium/drivers/vc4/vc4_qir.h b/src/gallium/drivers/vc4/vc4_qir.h
index 0c2bca93d8bc0f9ec4a534345fc0f968e51a3d1d..ebec7ccfbe34fb3f5329f4fdd66fd8fe7c4c9188 100644 (file)
--- a/src/gallium/drivers/vc4/vc4_qir.h
+++ b/src/gallium/drivers/vc4/vc4_qir.h
@@ -377,6 +377,7 @@ struct qreg qir_get_temp(struct vc4_compile *c);
 int qir_get_op_nsrc(enum qop qop);
 bool qir_reg_equals(struct qreg a, struct qreg b);
 bool qir_has_side_effects(struct vc4_compile *c, struct qinst *inst);
+bool qir_has_side_effect_reads(struct vc4_compile *c, struct qinst *inst);
 bool qir_is_multi_instruction(struct qinst *inst);
 bool qir_depends_on_flags(struct qinst *inst);
 bool qir_writes_r4(struct qinst *inst);