[Mesa-dev] [PATCH 1/5] i965: Move MRF register asserts out of brw_reg.h

[Iago Toral Quiroga]

In a later patch we will make BRW_MAX_MRF return a different value depending
on the hardware generation, but it is inconvenient to add a gen parameter
to the brw_reg functions only for the assertions, so move these to places where
we have the hardware generation available.

Ken suggested to add the asserts to brw_set_src0 and brw_set_dest since that
would make sure that we catch all uses of MRF registers, even those coming
from modules that generate native code directly, like blorp. Unfortunately,
this is very late in the process which can make things harder to debug, so add
asserts to the generator as well.
---
 src/mesa/drivers/dri/i965/brw_eu_emit.c          | 9 ++++++---
 src/mesa/drivers/dri/i965/brw_fs_generator.cpp   | 6 +++++-
 src/mesa/drivers/dri/i965/brw_reg.h              | 7 ++++---
 src/mesa/drivers/dri/i965/brw_vec4_generator.cpp | 3 +++
 4 files changed, 18 insertions(+), 7 deletions(-)

diff --git a/src/mesa/drivers/dri/i965/brw_eu_emit.c b/src/mesa/drivers/dri/i965/brw_eu_emit.c
index 0432efa..23a120e 100644
--- a/src/mesa/drivers/dri/i965/brw_eu_emit.c
+++ b/src/mesa/drivers/dri/i965/brw_eu_emit.c
@@ -146,8 +146,9 @@ brw_set_dest(struct brw_codegen *p, brw_inst *inst, struct brw_reg dest)
 {
    const struct brw_device_info *devinfo = p->devinfo;
 
-   if (dest.file != BRW_ARCHITECTURE_REGISTER_FILE &&
-       dest.file != BRW_MESSAGE_REGISTER_FILE)
+   if (dest.file == BRW_MESSAGE_REGISTER_FILE)
+      assert(dest.nr < BRW_MAX_MRF);
+   else if (dest.file != BRW_ARCHITECTURE_REGISTER_FILE)
       assert(dest.nr < 128);
 
    gen7_convert_mrf_to_grf(p, &dest);
@@ -309,7 +310,9 @@ brw_set_src0(struct brw_codegen *p, brw_inst *inst, struct brw_reg reg)
 {
    const struct brw_device_info *devinfo = p->devinfo;
 
-   if (reg.file != BRW_ARCHITECTURE_REGISTER_FILE)
+   if (reg.file == BRW_MESSAGE_REGISTER_FILE)
+      assert(reg.nr < BRW_MAX_MRF);
+   else if (reg.file != BRW_ARCHITECTURE_REGISTER_FILE)
       assert(reg.nr < 128);
 
    gen7_convert_mrf_to_grf(p, &reg);
diff --git a/src/mesa/drivers/dri/i965/brw_fs_generator.cpp b/src/mesa/drivers/dri/i965/brw_fs_generator.cpp
index 90805e4..a84cfc9 100644
--- a/src/mesa/drivers/dri/i965/brw_fs_generator.cpp
+++ b/src/mesa/drivers/dri/i965/brw_fs_generator.cpp
@@ -53,8 +53,10 @@ brw_reg_from_fs_reg(fs_inst *inst, fs_reg *reg)
    struct brw_reg brw_reg;
 
    switch (reg->file) {
-   case GRF:
    case MRF:
+      assert((reg->reg & ~(1 << 7)) < BRW_MAX_MRF);
+      /* Fallthrough */
+   case GRF:
       if (reg->stride == 0) {
          brw_reg = brw_vec1_reg(brw_file_from_reg(reg), reg->reg, 0);
       } else if (inst->exec_size < 8) {
@@ -1558,6 +1560,8 @@ fs_generator::generate_code(const cfg_t *cfg, int dispatch_width)
       brw_set_default_acc_write_control(p, inst->writes_accumulator);
       brw_set_default_exec_size(p, cvt(inst->exec_size) - 1);
 
+      assert(inst->base_mrf + inst->mlen <= BRW_MAX_MRF);
+
       switch (inst->exec_size) {
       case 1:
       case 2:
diff --git a/src/mesa/drivers/dri/i965/brw_reg.h b/src/mesa/drivers/dri/i965/brw_reg.h
index 31806f7..06d9269 100644
--- a/src/mesa/drivers/dri/i965/brw_reg.h
+++ b/src/mesa/drivers/dri/i965/brw_reg.h
@@ -344,10 +344,12 @@ brw_reg(unsigned file,
    struct brw_reg reg;
    if (file == BRW_GENERAL_REGISTER_FILE)
       assert(nr < BRW_MAX_GRF);
-   else if (file == BRW_MESSAGE_REGISTER_FILE)
-      assert((nr & ~(1 << 7)) < BRW_MAX_MRF);
    else if (file == BRW_ARCHITECTURE_REGISTER_FILE)
       assert(nr <= BRW_ARF_TIMESTAMP);
+   /* Asserting on the MRF register number requires to know the hardware gen
+    * (gen6 has 24 MRF registers), which we don't know here, so we assert
+    * for that in the generators and in brw_eu_emit.c
+    */
 
    reg.type = type;
    reg.file = file;
@@ -808,7 +810,6 @@ brw_mask_reg(unsigned subnr)
 static inline struct brw_reg
 brw_message_reg(unsigned nr)
 {
-   assert((nr & ~(1 << 7)) < BRW_MAX_MRF);
    return brw_vec8_reg(BRW_MESSAGE_REGISTER_FILE, nr, 0);
 }
 
diff --git a/src/mesa/drivers/dri/i965/brw_vec4_generator.cpp b/src/mesa/drivers/dri/i965/brw_vec4_generator.cpp
index 1950333..0a95530 100644
--- a/src/mesa/drivers/dri/i965/brw_vec4_generator.cpp
+++ b/src/mesa/drivers/dri/i965/brw_vec4_generator.cpp
@@ -46,6 +46,7 @@ vec4_instruction::get_dst(void)
       break;
 
    case MRF:
+      assert(((dst.reg + dst.reg_offset) & ~(1 << 7)) < BRW_MAX_MRF);
       brw_reg = brw_message_reg(dst.reg + dst.reg_offset);
       brw_reg = retype(brw_reg, dst.type);
       brw_reg.dw1.bits.writemask = dst.writemask;
@@ -1134,6 +1135,8 @@ vec4_generator::generate_code(const cfg_t *cfg)
       brw_set_default_mask_control(p, inst->force_writemask_all);
       brw_set_default_acc_write_control(p, inst->writes_accumulator);
 
+      assert(inst->base_mrf + inst->mlen <= BRW_MAX_MRF);
+
       unsigned pre_emit_nr_insn = p->nr_insn;
 
       if (dst.width == BRW_WIDTH_4) {
-- 
1.9.1