pan/va: Add instruction selection lowering pass

Valhall removes certain instructions from Bifrost, requiring a canonical
lowering.

Signed-off-by: Alyssa Rosenzweig <alyssa@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/15223>

diff --git a/src/panfrost/bifrost/meson.build b/src/panfrost/bifrost/meson.build
index 0bc5222c17557282879e6b50bc2e8d8359431b68..c5de4927d199724bcccdd34b545b34956563903d 100644 (file)
--- a/src/panfrost/bifrost/meson.build
+++ b/src/panfrost/bifrost/meson.build
@@ -46,6 +46,7 @@ libpanfrost_bifrost_files = files(
   'bir.c',
   'bifrost_compile.c',
   'valhall/va_lower_constants.c',
+  'valhall/va_lower_isel.c',
   'valhall/va_optimize.c',
   'valhall/va_pack.c',
   'valhall/va_validate.c',

diff --git a/src/panfrost/bifrost/valhall/va_compiler.h b/src/panfrost/bifrost/valhall/va_compiler.h
index 59b7634e092c0ce2af6b255e530c1e40951158ca..b346561b875a0327b0282b84be7f9c9232336f83 100644 (file)
--- a/src/panfrost/bifrost/valhall/va_compiler.h
+++ b/src/panfrost/bifrost/valhall/va_compiler.h
@@ -39,6 +39,7 @@ void va_validate(FILE *fp, bi_context *ctx);
 void va_repair_fau(bi_builder *b, bi_instr *I);
 void va_fuse_add_imm(bi_instr *I);
 void va_lower_constants(bi_context *ctx, bi_instr *I);
+void va_lower_isel(bi_instr *I);
 uint64_t va_pack_instr(const bi_instr *I, unsigned flow);
 
 static inline unsigned

diff --git a/src/panfrost/bifrost/valhall/va_lower_isel.c b/src/panfrost/bifrost/valhall/va_lower_isel.c
new file mode 100644 (file)
index 0000000..4ad22f6
--- /dev/null
+++ b/src/panfrost/bifrost/valhall/va_lower_isel.c
@@ -0,0 +1,116 @@
+/*
+ * Copyright (C) 2021 Collabora Ltd.
+ *
+ * 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 "va_compiler.h"
+#include "valhall.h"
+#include "bi_builder.h"
+
+void
+va_lower_isel(bi_instr *I)
+{
+   switch (I->op) {
+
+   /* Integer addition has swizzles and addition with 0 is canonical swizzle */
+   case BI_OPCODE_SWZ_V2I16:
+      I->op = BI_OPCODE_IADD_V2U16;
+      I->src[1] = bi_zero();
+      break;
+
+   case BI_OPCODE_SWZ_V4I8:
+      I->op = BI_OPCODE_IADD_V4U8;
+      I->src[1] = bi_zero();
+      break;
+
+   /* Needs to output the coverage mask */
+   case BI_OPCODE_DISCARD_F32:
+      assert(bi_is_null(I->dest[0]));
+      I->dest[0] = bi_register(60);
+      break;
+
+   /* Extra source in Valhall not yet modeled in the Bifrost IR */
+   case BI_OPCODE_ICMP_I32:
+      I->op = BI_OPCODE_ICMP_U32;
+      I->src[2] = bi_zero();
+      break;
+
+   case BI_OPCODE_ICMP_V2I16:
+      I->op = BI_OPCODE_ICMP_V2U16;
+      I->src[2] = bi_zero();
+      break;
+
+   case BI_OPCODE_ICMP_V4I8:
+      I->op = BI_OPCODE_ICMP_V4U8;
+      I->src[2] = bi_zero();
+      break;
+
+   case BI_OPCODE_ICMP_U32:
+   case BI_OPCODE_ICMP_V2U16:
+   case BI_OPCODE_ICMP_V4U8:
+   case BI_OPCODE_ICMP_S32:
+   case BI_OPCODE_ICMP_V2S16:
+   case BI_OPCODE_ICMP_V4S8:
+   case BI_OPCODE_FCMP_F32:
+   case BI_OPCODE_FCMP_V2F16:
+      I->src[2] = bi_zero();
+      break;
+
+   /* Integer CSEL must have a signedness */
+   case BI_OPCODE_CSEL_I32:
+   case BI_OPCODE_CSEL_V2I16:
+      assert(I->cmpf == BI_CMPF_EQ || I->cmpf == BI_CMPF_NE);
+
+      I->op = (I->op == BI_OPCODE_CSEL_I32) ? BI_OPCODE_CSEL_U32 :
+              BI_OPCODE_CSEL_V2U16;
+      break;
+
+   /* Jump -> conditional branch with condition tied to true. */
+   case BI_OPCODE_JUMP:
+      I->op = I->branch_target ? BI_OPCODE_BRANCHZ_I16 : BI_OPCODE_BRANCHZI;
+      I->src[1] = I->src[0];
+      I->src[0] = bi_zero();
+      I->cmpf = BI_CMPF_EQ;
+      break;
+
+   case BI_OPCODE_AXCHG_I32:
+      I->op = BI_OPCODE_ATOM_RETURN_I32;
+      I->atom_opc = BI_ATOM_OPC_AXCHG;
+      I->sr_count = 1;
+      break;
+
+   case BI_OPCODE_ACMPXCHG_I32:
+      I->op = BI_OPCODE_ATOM_RETURN_I32;
+      I->atom_opc = BI_ATOM_OPC_ACMPXCHG;
+      /* Reads 2, this is special cased in bir.c */
+      I->sr_count = 1;
+      break;
+
+   case BI_OPCODE_ATOM_RETURN_I32:
+      if (bi_is_null(I->dest[0]))
+         I->op = BI_OPCODE_ATOM_I32;
+
+      break;
+
+   default:
+      break;
+   }
+}