vc4: Replace the SSA-style SEL operators with conditional MOVs.

I'm moving away from QIR being SSA (since NIR is doing lots of SSA
optimization for us now) and instead having QIR just be QPU operations
with virtual registers.  By making our SELs be composed of two MOVs, we
could potentially coalesce the registers for the MOV's src and dst and
eliminate the MOV.

total instructions in shared programs: 88448 -> 88028 (-0.47%)
instructions in affected programs:     39845 -> 39425 (-1.05%)
total estimated cycles in shared programs: 246306 -> 245762 (-0.22%)
estimated cycles in affected programs:     162887 -> 162343 (-0.33%)

1 files changed, 18 insertions, 32 deletions

diff --git a/src/gallium/drivers/vc4/vc4_qir.h b/src/gallium/drivers/vc4/vc4_qir.h
index b0fbb4c1db2..9dad80dddff 100644
--- a/src/gallium/drivers/vc4/vc4_qir.h
+++ b/src/gallium/drivers/vc4/vc4_qir.h
@@ -93,23 +93,6 @@ enum qop {
         QOP_XOR,
         QOP_NOT,
 
-        /* Note: Orderings of these compares must be the same as in
-         * qpu_defines.h.  Selects the src[0] if the ns flag bit is set,
-         * otherwise 0. */
-        QOP_SEL_X_0_ZS,
-        QOP_SEL_X_0_ZC,
-        QOP_SEL_X_0_NS,
-        QOP_SEL_X_0_NC,
-        QOP_SEL_X_0_CS,
-        QOP_SEL_X_0_CC,
-        /* Selects the src[0] if the ns flag bit is set, otherwise src[1]. */
-        QOP_SEL_X_Y_ZS,
-        QOP_SEL_X_Y_ZC,
-        QOP_SEL_X_Y_NS,
-        QOP_SEL_X_Y_NC,
-        QOP_SEL_X_Y_CS,
-        QOP_SEL_X_Y_CC,
-
         QOP_FTOI,
         QOP_ITOF,
         QOP_RCP,
@@ -170,6 +153,7 @@ struct qinst {
         struct qreg dst;
         struct qreg *src;
         bool sf;
+        uint8_t cond;
 };
 
 enum qstage {
@@ -463,9 +447,11 @@ void qir_schedule_instructions(struct vc4_compile *c);
 void qir_reorder_uniforms(struct vc4_compile *c);
 
 void qir_emit(struct vc4_compile *c, struct qinst *inst);
-static inline void qir_emit_nodef(struct vc4_compile *c, struct qinst *inst)
+static inline struct qinst *
+qir_emit_nodef(struct vc4_compile *c, struct qinst *inst)
 {
         list_addtail(&inst->link, &c->instructions);
+        return inst;
 }
 
 struct qreg qir_get_temp(struct vc4_compile *c);
@@ -536,11 +522,12 @@ qir_##name(struct vc4_compile *c, struct qreg a)                         \
         qir_emit(c, qir_inst(QOP_##name, t, a, c->undef));               \
         return t;                                                        \
 }                                                                        \
-static inline void                                                       \
+static inline struct qinst *                                             \
 qir_##name##_dest(struct vc4_compile *c, struct qreg dest,               \
                   struct qreg a)                                         \
 {                                                                        \
-        qir_emit_nodef(c, qir_inst(QOP_##name, dest, a, c->undef));      \
+        return qir_emit_nodef(c, qir_inst(QOP_##name, dest, a,           \
+                                          c->undef));                    \
 }
 
 #define QIR_ALU2(name)                                                   \
@@ -592,18 +579,6 @@ QIR_ALU2(V8MAX)
 QIR_ALU2(V8ADDS)
 QIR_ALU2(V8SUBS)
 QIR_ALU2(MUL24)
-QIR_ALU1(SEL_X_0_ZS)
-QIR_ALU1(SEL_X_0_ZC)
-QIR_ALU1(SEL_X_0_NS)
-QIR_ALU1(SEL_X_0_NC)
-QIR_ALU1(SEL_X_0_CS)
-QIR_ALU1(SEL_X_0_CC)
-QIR_ALU2(SEL_X_Y_ZS)
-QIR_ALU2(SEL_X_Y_ZC)
-QIR_ALU2(SEL_X_Y_NS)
-QIR_ALU2(SEL_X_Y_NC)
-QIR_ALU2(SEL_X_Y_CS)
-QIR_ALU2(SEL_X_Y_CC)
 QIR_ALU2(FMIN)
 QIR_ALU2(FMAX)
 QIR_ALU2(FMINABS)
@@ -648,6 +623,17 @@ QIR_NODST_1(TLB_STENCIL_SETUP)
 QIR_NODST_1(MS_MASK)
 
 static inline struct qreg
+qir_SEL(struct vc4_compile *c, uint8_t cond, struct qreg src0, struct qreg src1)
+{
+        struct qreg t = qir_get_temp(c);
+        struct qinst *a = qir_MOV_dest(c, t, src0);
+        struct qinst *b = qir_MOV_dest(c, t, src1);
+        a->cond = cond;
+        b->cond = cond ^ 1;
+        return t;
+}
+
+static inline struct qreg
 qir_UNPACK_8_F(struct vc4_compile *c, struct qreg src, int i)
 {
         struct qreg t = qir_FMOV(c, src);