Mesa (master): pan/midgard: Fix masks/alignment for 64-bit loads

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Module: Mesa
Branch: master
Commit: 1798f6bfc33d1d77dae1112591dce18bf7fdbc4a
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=1798f6bfc33d1d77dae1112591dce18bf7fdbc4a

Author: Alyssa Rosenzweig <alyssa.rosenzweig at collabora.com>
Date:   Fri Nov 15 15:16:53 2019 -0500

pan/midgard: Fix masks/alignment for 64-bit loads

These need to be handled with special care.

Oh, Midgard, you're *extra* special.

Signed-off-by: Alyssa Rosenzweig <alyssa.rosenzweig at collabora.com>

---

 src/panfrost/midgard/compiler.h             |  3 +++
 src/panfrost/midgard/midgard_compile.c      | 28 ++++++++++++++++++++--------
 src/panfrost/midgard/midgard_ra.c           | 13 +++++++++----
 src/panfrost/midgard/mir_promote_uniforms.c |  6 +++++-
 4 files changed, 37 insertions(+), 13 deletions(-)

diff --git a/src/panfrost/midgard/compiler.h b/src/panfrost/midgard/compiler.h
index 3c70f071814..3c1730143e2 100644
--- a/src/panfrost/midgard/compiler.h
+++ b/src/panfrost/midgard/compiler.h
@@ -144,6 +144,9 @@ typedef struct midgard_instruction {
         unsigned nr_dependencies;
         BITSET_WORD *dependents;
 
+        /* For load/store ops.. force 64-bit destination */
+        bool load_64;
+
         union {
                 midgard_load_store_word load_store;
                 midgard_vector_alu alu;
diff --git a/src/panfrost/midgard/midgard_compile.c b/src/panfrost/midgard/midgard_compile.c
index 19573900bd9..a187beaab7c 100644
--- a/src/panfrost/midgard/midgard_compile.c
+++ b/src/panfrost/midgard/midgard_compile.c
@@ -1104,15 +1104,27 @@ emit_alu(compiler_context *ctx, nir_alu_instr *instr)
 
 #undef ALU_CASE
 
-static unsigned
-mir_mask_for_intr(nir_instr *instr, bool is_read)
+static void
+mir_set_intr_mask(nir_instr *instr, midgard_instruction *ins, bool is_read)
 {
         nir_intrinsic_instr *intr = nir_instr_as_intrinsic(instr);
+        unsigned nir_mask = 0;
+        unsigned dsize = 0;
 
-        if (is_read)
-                return mask_of(nir_intrinsic_dest_components(intr));
-        else
-                return nir_intrinsic_write_mask(intr);
+        if (is_read) {
+                nir_mask = mask_of(nir_intrinsic_dest_components(intr));
+                dsize = nir_dest_bit_size(intr->dest);
+        } else {
+                nir_mask = nir_intrinsic_write_mask(intr);
+                dsize = 32;
+        }
+
+        /* Once we have the NIR mask, we need to normalize to work in 32-bit space */
+        unsigned bytemask = mir_to_bytemask(mir_mode_for_destsize(dsize), nir_mask);
+        mir_set_bytemask(ins, bytemask);
+
+        if (dsize == 64)
+                ins->load_64 = true;
 }
 
 /* Uniforms and UBOs use a shared code path, as uniforms are just (slightly
@@ -1134,7 +1146,7 @@ emit_ubo_read(
         /* TODO: Don't split */
         ins.load_store.varying_parameters = (offset & 0x7F) << 3;
         ins.load_store.address = offset >> 7;
-        ins.mask = mir_mask_for_intr(instr, true);
+        mir_set_intr_mask(instr, &ins, true);
 
         if (indirect_offset) {
                 ins.src[2] = nir_src_index(ctx, indirect_offset);
@@ -1204,7 +1216,7 @@ emit_ssbo_access(
 
         ins.load_store.varying_parameters = (offset & 0x1FF) << 1;
         ins.load_store.address = (offset >> 9);
-        ins.mask = mir_mask_for_intr(instr, is_read);
+        mir_set_intr_mask(instr, &ins, is_read);
 
         emit_mir_instruction(ctx, ins);
 }
diff --git a/src/panfrost/midgard/midgard_ra.c b/src/panfrost/midgard/midgard_ra.c
index 85ad96ff312..c2c1874aa82 100644
--- a/src/panfrost/midgard/midgard_ra.c
+++ b/src/panfrost/midgard/midgard_ra.c
@@ -452,6 +452,7 @@ allocate_registers(compiler_context *ctx, bool *spilled)
         }
 
         unsigned *found_class = calloc(sizeof(unsigned), ctx->temp_count);
+        unsigned *min_alignment = calloc(sizeof(unsigned), ctx->temp_count);
 
         mir_foreach_instr_global(ctx, ins) {
                 if (ins->dest >= SSA_FIXED_MINIMUM) continue;
@@ -465,17 +466,21 @@ allocate_registers(compiler_context *ctx, bool *spilled)
                 int dest = ins->dest;
                 found_class[dest] = MAX2(found_class[dest], class);
 
-                lcra_set_alignment(l, dest, 2); /* (1 << 2) = 4 */
-
                 /* XXX: Ensure swizzles align the right way with more LCRA constraints? */
                 if (ins->type == TAG_ALU_4 && ins->alu.reg_mode != midgard_reg_mode_32)
-                        lcra_set_alignment(l, dest, 3); /* (1 << 3) = 8 */
+                        min_alignment[dest] = 3; /* (1 << 3) = 8 */
+
+                if (ins->type == TAG_LOAD_STORE_4 && ins->load_64)
+                        min_alignment[dest] = 3;
         }
 
-        for (unsigned i = 0; i < ctx->temp_count; ++i)
+        for (unsigned i = 0; i < ctx->temp_count; ++i) {
+                lcra_set_alignment(l, i, min_alignment[i] ? min_alignment[i] : 2);
                 lcra_restrict_range(l, i, (found_class[i] + 1) * 4);
+        }
         
         free(found_class);
+        free(min_alignment);
 
         /* Next, we'll determine semantic class. We default to zero (work).
          * But, if we're used with a special operation, that will force us to a
diff --git a/src/panfrost/midgard/mir_promote_uniforms.c b/src/panfrost/midgard/mir_promote_uniforms.c
index b10717852e5..8d887a615fb 100644
--- a/src/panfrost/midgard/mir_promote_uniforms.c
+++ b/src/panfrost/midgard/mir_promote_uniforms.c
@@ -89,7 +89,11 @@ midgard_promote_uniforms(compiler_context *ctx, unsigned promoted_count)
 
                 if (needs_move) {
                         midgard_instruction mov = v_mov(promoted, ins->dest);
-                        mov.mask = ins->mask;
+
+                        if (ins->load_64)
+                                mov.alu.reg_mode = midgard_reg_mode_64;
+
+                        mir_set_bytemask(&mov, mir_bytemask(ins));
                         mir_insert_instruction_before(ctx, ins, mov);
                 } else {
                         mir_rewrite_index_src(ctx, ins->dest, promoted);