vc4: Add a small QIR validate pass.

This has caught a couple of bugs during loop development so far, and I
should probably have written it long ago.

4 files changed, 127 insertions, 0 deletions

diff --git a/src/gallium/drivers/vc4/Makefile.sources b/src/gallium/drivers/vc4/Makefile.sources
index 78d77c6b288..0d1d4f799dc 100644
--- a/src/gallium/drivers/vc4/Makefile.sources
+++ b/src/gallium/drivers/vc4/Makefile.sources
@@ -32,6 +32,7 @@ C_SOURCES := \
 	vc4_qir.c \
 	vc4_qir_lower_uniforms.c \
 	vc4_qir_schedule.c \
+	vc4_qir_validate.c \
 	vc4_qir.h \
 	vc4_qpu.c \
 	vc4_qpu_defines.h \
diff --git a/src/gallium/drivers/vc4/vc4_qir.c b/src/gallium/drivers/vc4/vc4_qir.c
index 4b185be0b65..86a7ae023c1 100644
--- a/src/gallium/drivers/vc4/vc4_qir.c
+++ b/src/gallium/drivers/vc4/vc4_qir.c
@@ -518,6 +518,7 @@ qir_SF(struct vc4_compile *c, struct qreg src)
                                         "QIR opt pass %2d: %s progress\n", \
                                         pass, #func);                   \
                         }                                               \
+                        qir_validate(c);                                \
                 }                                                       \
         } while (0)
 
diff --git a/src/gallium/drivers/vc4/vc4_qir.h b/src/gallium/drivers/vc4/vc4_qir.h
index 04ca8ed7f4b..d1263b64362 100644
--- a/src/gallium/drivers/vc4/vc4_qir.h
+++ b/src/gallium/drivers/vc4/vc4_qir.h
@@ -480,6 +480,8 @@ void qir_dump(struct vc4_compile *c);
 void qir_dump_inst(struct vc4_compile *c, struct qinst *inst);
 const char *qir_get_stage_name(enum qstage stage);
 
+void qir_validate(struct vc4_compile *c);
+
 void qir_optimize(struct vc4_compile *c);
 bool qir_opt_algebraic(struct vc4_compile *c);
 bool qir_opt_constant_folding(struct vc4_compile *c);
diff --git a/src/gallium/drivers/vc4/vc4_qir_validate.c b/src/gallium/drivers/vc4/vc4_qir_validate.c
new file mode 100644
index 00000000000..f41cd634027
--- /dev/null
+++ b/src/gallium/drivers/vc4/vc4_qir_validate.c
@@ -0,0 +1,123 @@
+/*
+ * Copyright © 2016 Broadcom Limited
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ */
+
+#include "vc4_qir.h"
+#include "vc4_qpu.h"
+
+static void
+fail_instr(struct qinst *inst, const char *msg)
+{
+        fprintf(stderr, "qir_validate: %s: ", msg);
+        qir_dump_inst(stderr, inst);
+        fprintf(stderr, "\n");
+        abort();
+}
+
+void qir_validate(struct vc4_compile *c)
+{
+        bool already_assigned[c->num_temps];
+        memset(&already_assigned, 0, sizeof(already_assigned));
+
+        /* We don't want to do validation in release builds, but we want to
+         * keep compiling the validation code to make sure it doesn't get
+         * broken.
+         */
+#ifndef DEBUG
+        return;
+#endif
+
+        for (int i = 0; i < c->num_temps; i++) {
+                struct qinst *def = c->defs[i];
+
+                if (def && def->cond != QPU_COND_ALWAYS)
+                        fail_instr(def, "SSA def with condition");
+        }
+
+        list_for_each_entry(struct qinst, inst, &c->instructions, link) {
+                switch (inst->dst.file) {
+                case QFILE_TEMP:
+                        if (inst->dst.index >= c->num_temps)
+                                fail_instr(inst, "bad temp index");
+
+                        if (c->defs[inst->dst.index] &&
+                            already_assigned[inst->dst.index]) {
+                                fail_instr(inst, "Re-assignment of SSA value");
+                        }
+                        already_assigned[inst->dst.index] = true;
+                        break;
+
+                case QFILE_NULL:
+                case QFILE_VPM:
+                case QFILE_TLB_COLOR_WRITE:
+                case QFILE_TLB_COLOR_WRITE_MS:
+                case QFILE_TLB_Z_WRITE:
+                case QFILE_TLB_STENCIL_SETUP:
+                        break;
+
+                case QFILE_VARY:
+                case QFILE_UNIF:
+                case QFILE_FRAG_X:
+                case QFILE_FRAG_Y:
+                case QFILE_FRAG_REV_FLAG:
+                case QFILE_SMALL_IMM:
+                        fail_instr(inst, "Bad dest file");
+                        break;
+                }
+
+                for (int i = 0; i < qir_get_op_nsrc(inst->op); i++) {
+                        struct qreg src = inst->src[i];
+
+                        switch (src.file) {
+                        case QFILE_TEMP:
+                                if (src.index >= c->num_temps)
+                                        fail_instr(inst, "bad temp index");
+                                break;
+
+                        case QFILE_VARY:
+                        case QFILE_UNIF:
+                        case QFILE_VPM:
+                                break;
+
+                        case QFILE_SMALL_IMM:
+                                if (qpu_encode_small_immediate(src.index) == ~0)
+                                        fail_instr(inst, "bad small immediate");
+                                break;
+
+                        case QFILE_FRAG_X:
+                        case QFILE_FRAG_Y:
+                        case QFILE_FRAG_REV_FLAG:
+                                if (c->stage != QSTAGE_FRAG)
+                                        fail_instr(inst, "frag access in VS/CS");
+                                break;
+
+                        case QFILE_NULL:
+                        case QFILE_TLB_COLOR_WRITE:
+                        case QFILE_TLB_COLOR_WRITE_MS:
+                        case QFILE_TLB_Z_WRITE:
+                        case QFILE_TLB_STENCIL_SETUP:
+                                fail_instr(inst, "Bad src file");
+                                break;
+                        }
+                }
+        }
+}