Mesa (master): vc4: Set unused raddr fields to QPU_R_NOP.

[Eric Anholt]

Module: Mesa
Branch: master
Commit: 84caf5a8617b99b6453fb66cb371a89ea2205dba
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=84caf5a8617b99b6453fb66cb371a89ea2205dba

Author: Eric Anholt <eric at anholt.net>
Date:   Thu Oct  2 23:32:59 2014 -0700

vc4: Set unused raddr fields to QPU_R_NOP.

The simulator assertion fails if you have a write to a reg and then a read
(for example, in the NOP side of an instruction), even if the read isn't
used for anything.  By setting unused raddrs to NOP, we avoid the problem
(since only the phsyical registers are tracked).

---

 src/gallium/drivers/vc4/vc4_qpu.c |   43 +++++++++++++++++++++++--------------
 1 file changed, 27 insertions(+), 16 deletions(-)

diff --git a/src/gallium/drivers/vc4/vc4_qpu.c b/src/gallium/drivers/vc4/vc4_qpu.c
index 27fc309..a551a0f 100644
--- a/src/gallium/drivers/vc4/vc4_qpu.c
+++ b/src/gallium/drivers/vc4/vc4_qpu.c
@@ -28,18 +28,17 @@ static uint64_t
 set_src_raddr(uint64_t inst, struct qpu_reg src)
 {
         if (src.mux == QPU_MUX_A) {
-                /* These asserts could be better, checking to be sure we're
-                 * not overwriting an actual use of a raddr of 0.
-                 */
-                assert(QPU_GET_FIELD(inst, QPU_RADDR_A) == 0 ||
+                assert(QPU_GET_FIELD(inst, QPU_RADDR_A) == QPU_R_NOP ||
                        QPU_GET_FIELD(inst, QPU_RADDR_A) == src.addr);
-                return inst | QPU_SET_FIELD(src.addr, QPU_RADDR_A);
+                return ((inst & ~QPU_RADDR_A_MASK) |
+                        QPU_SET_FIELD(src.addr, QPU_RADDR_A));
         }
 
         if (src.mux == QPU_MUX_B) {
-                assert(QPU_GET_FIELD(inst, QPU_RADDR_B) == 0 ||
+                assert(QPU_GET_FIELD(inst, QPU_RADDR_B) == QPU_R_NOP ||
                        QPU_GET_FIELD(inst, QPU_RADDR_B) == src.addr);
-                return inst | QPU_SET_FIELD(src.addr, QPU_RADDR_B);
+                return ((inst & ~QPU_RADDR_B_MASK) |
+                        QPU_SET_FIELD(src.addr, QPU_RADDR_B));
         }
 
         return inst;
@@ -56,6 +55,8 @@ qpu_NOP()
         /* Note: These field values are actually non-zero */
         inst |= QPU_SET_FIELD(QPU_W_NOP, QPU_WADDR_ADD);
         inst |= QPU_SET_FIELD(QPU_W_NOP, QPU_WADDR_MUL);
+        inst |= QPU_SET_FIELD(QPU_R_NOP, QPU_RADDR_A);
+        inst |= QPU_SET_FIELD(QPU_R_NOP, QPU_RADDR_B);
         inst |= QPU_SET_FIELD(QPU_SIG_NONE, QPU_SIG);
 
         return inst;
@@ -101,11 +102,13 @@ qpu_a_MOV(struct qpu_reg dst, struct qpu_reg src)
         uint64_t inst = 0;
 
         inst |= QPU_SET_FIELD(QPU_A_OR, QPU_OP_ADD);
+        inst |= QPU_SET_FIELD(QPU_R_NOP, QPU_RADDR_A);
+        inst |= QPU_SET_FIELD(QPU_R_NOP, QPU_RADDR_B);
         inst |= qpu_a_dst(dst);
         inst |= QPU_SET_FIELD(QPU_COND_ALWAYS, QPU_COND_ADD);
         inst |= QPU_SET_FIELD(src.mux, QPU_ADD_A);
         inst |= QPU_SET_FIELD(src.mux, QPU_ADD_B);
-        inst |= set_src_raddr(inst, src);
+        inst = set_src_raddr(inst, src);
         inst |= QPU_SET_FIELD(QPU_SIG_NONE, QPU_SIG);
         inst |= QPU_SET_FIELD(QPU_W_NOP, QPU_WADDR_MUL);
 
@@ -118,11 +121,13 @@ qpu_m_MOV(struct qpu_reg dst, struct qpu_reg src)
         uint64_t inst = 0;
 
         inst |= QPU_SET_FIELD(QPU_M_V8MIN, QPU_OP_MUL);
+        inst |= QPU_SET_FIELD(QPU_R_NOP, QPU_RADDR_A);
+        inst |= QPU_SET_FIELD(QPU_R_NOP, QPU_RADDR_B);
         inst |= qpu_m_dst(dst);
         inst |= QPU_SET_FIELD(QPU_COND_ALWAYS, QPU_COND_MUL);
         inst |= QPU_SET_FIELD(src.mux, QPU_MUL_A);
         inst |= QPU_SET_FIELD(src.mux, QPU_MUL_B);
-        inst |= set_src_raddr(inst, src);
+        inst = set_src_raddr(inst, src);
         inst |= QPU_SET_FIELD(QPU_SIG_NONE, QPU_SIG);
         inst |= QPU_SET_FIELD(QPU_W_NOP, QPU_WADDR_ADD);
 
@@ -151,12 +156,14 @@ qpu_a_alu2(enum qpu_op_add op,
         uint64_t inst = 0;
 
         inst |= QPU_SET_FIELD(op, QPU_OP_ADD);
+        inst |= QPU_SET_FIELD(QPU_R_NOP, QPU_RADDR_A);
+        inst |= QPU_SET_FIELD(QPU_R_NOP, QPU_RADDR_B);
         inst |= qpu_a_dst(dst);
         inst |= QPU_SET_FIELD(QPU_COND_ALWAYS, QPU_COND_ADD);
         inst |= QPU_SET_FIELD(src0.mux, QPU_ADD_A);
-        inst |= set_src_raddr(inst, src0);
+        inst = set_src_raddr(inst, src0);
         inst |= QPU_SET_FIELD(src1.mux, QPU_ADD_B);
-        inst |= set_src_raddr(inst, src1);
+        inst = set_src_raddr(inst, src1);
         inst |= QPU_SET_FIELD(QPU_SIG_NONE, QPU_SIG);
         inst |= QPU_SET_FIELD(QPU_W_NOP, QPU_WADDR_MUL);
 
@@ -169,16 +176,15 @@ qpu_m_alu2(enum qpu_op_mul op,
 {
         uint64_t inst = 0;
 
-        set_src_raddr(inst, src0);
-        set_src_raddr(inst, src1);
-
         inst |= QPU_SET_FIELD(op, QPU_OP_MUL);
+        inst |= QPU_SET_FIELD(QPU_R_NOP, QPU_RADDR_A);
+        inst |= QPU_SET_FIELD(QPU_R_NOP, QPU_RADDR_B);
         inst |= qpu_m_dst(dst);
         inst |= QPU_SET_FIELD(QPU_COND_ALWAYS, QPU_COND_MUL);
         inst |= QPU_SET_FIELD(src0.mux, QPU_MUL_A);
-        inst |= set_src_raddr(inst, src0);
+        inst = set_src_raddr(inst, src0);
         inst |= QPU_SET_FIELD(src1.mux, QPU_MUL_B);
-        inst |= set_src_raddr(inst, src1);
+        inst = set_src_raddr(inst, src1);
         inst |= QPU_SET_FIELD(QPU_SIG_NONE, QPU_SIG);
         inst |= QPU_SET_FIELD(QPU_W_NOP, QPU_WADDR_ADD);
 
@@ -209,6 +215,11 @@ qpu_inst(uint64_t add, uint64_t mul)
         merge = merge_fields(merge, add, mul, QPU_SIG_MASK,
                              QPU_SET_FIELD(QPU_SIG_NONE, QPU_SIG));
 
+        merge = merge_fields(merge, add, mul, QPU_RADDR_A_MASK,
+                             QPU_SET_FIELD(QPU_R_NOP, QPU_RADDR_A));
+        merge = merge_fields(merge, add, mul, QPU_RADDR_B_MASK,
+                             QPU_SET_FIELD(QPU_R_NOP, QPU_RADDR_B));
+
         return merge;
 }