From 377bf3a5a4c35246385c762b0a8c88966ca3ac61 Mon Sep 17 00:00:00 2001
From: Alyssa Rosenzweig <alyssa@collabora.com>
Date: Fri, 24 Jun 2022 09:07:42 -0400
Subject: [PATCH] pan/bi: Lower swizzles for 8-bit shifts

Fixes integers_ops.integer_ctz

Signed-off-by: Alyssa Rosenzweig <alyssa@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/18656>
---
 src/panfrost/bifrost/bi_lower_swizzle.c       | 41 ++++++++++++-------
 .../bifrost/test/test-lower-swizzle.cpp       | 23 +++++++++++
 2 files changed, 50 insertions(+), 14 deletions(-)

diff --git a/src/panfrost/bifrost/bi_lower_swizzle.c b/src/panfrost/bifrost/bi_lower_swizzle.c
index d5b096a58ed..53ea4ff357a 100644
--- a/src/panfrost/bifrost/bi_lower_swizzle.c
+++ b/src/panfrost/bifrost/bi_lower_swizzle.c
@@ -30,6 +30,20 @@
  * recombine swizzles where we can as an optimization.
  */
 
+static bool
+bi_swizzle_replicates_8(enum bi_swizzle swz)
+{
+        switch (swz) {
+        case BI_SWIZZLE_B0000:
+        case BI_SWIZZLE_B1111:
+        case BI_SWIZZLE_B2222:
+        case BI_SWIZZLE_B3333:
+                return true;
+        default:
+                return false;
+        }
+}
+
 static void
 lower_swizzle(bi_context *ctx, bi_instr *ins, unsigned src)
 {
@@ -99,6 +113,19 @@ lower_swizzle(bi_context *ctx, bi_instr *ins, unsigned src)
         case BI_OPCODE_IADD_IMM_V4I8:
                 break;
 
+        case BI_OPCODE_LSHIFT_AND_V4I8:
+        case BI_OPCODE_LSHIFT_OR_V4I8:
+        case BI_OPCODE_LSHIFT_XOR_V4I8:
+        case BI_OPCODE_RSHIFT_AND_V4I8:
+        case BI_OPCODE_RSHIFT_OR_V4I8:
+        case BI_OPCODE_RSHIFT_XOR_V4I8:
+                /* Last source allows identity or replication */
+                if (src == 2 && bi_swizzle_replicates_8(ins->src[src].swizzle))
+                        return;
+
+                /* Others do not allow swizzles */
+                break;
+
         /* We don't want to deal with reswizzling logic in modifier prop. Move
          * the swizzle outside, it's easier for clamp propagation. */
         case BI_OPCODE_FCLAMP_V2F16:
@@ -149,20 +176,6 @@ lower_swizzle(bi_context *ctx, bi_instr *ins, unsigned src)
         ins->src[src].swizzle = BI_SWIZZLE_H01;
 }
 
-static bool
-bi_swizzle_replicates_8(enum bi_swizzle swz)
-{
-        switch (swz) {
-        case BI_SWIZZLE_B0000:
-        case BI_SWIZZLE_B1111:
-        case BI_SWIZZLE_B2222:
-        case BI_SWIZZLE_B3333:
-                return true;
-        default:
-                return false;
-        }
-}
-
 static bool
 bi_swizzle_replicates_16(enum bi_swizzle swz)
 {
diff --git a/src/panfrost/bifrost/test/test-lower-swizzle.cpp b/src/panfrost/bifrost/test/test-lower-swizzle.cpp
index d8abd77358e..18473fc7bb0 100644
--- a/src/panfrost/bifrost/test/test-lower-swizzle.cpp
+++ b/src/panfrost/bifrost/test/test-lower-swizzle.cpp
@@ -75,3 +75,26 @@ TEST_F(LowerSwizzle, ClzHadd8)
    CASE(bi_hadd_v4u8_to(b, reg, y, x3210, BI_ROUND_RTP),
         bi_hadd_v4u8_to(b, reg, y, bi_swz_v4i8(b, x3210), BI_ROUND_RTP));
 }
+
+TEST_F(LowerSwizzle, FirstShift8)
+{
+   enum bi_opcode ops[] = {
+      BI_OPCODE_LSHIFT_AND_V4I8,
+      BI_OPCODE_LSHIFT_OR_V4I8,
+      BI_OPCODE_LSHIFT_XOR_V4I8,
+      BI_OPCODE_RSHIFT_AND_V4I8,
+      BI_OPCODE_RSHIFT_OR_V4I8,
+      BI_OPCODE_RSHIFT_XOR_V4I8,
+   };
+
+   for (unsigned i = 0; i < ARRAY_SIZE(ops); ++i) {
+      CASE({
+            bi_instr *I = bi_lshift_and_v4i8_to(b, reg, x3210, y, z);
+            I->op = ops[i];
+      },
+      {
+            bi_instr *I = bi_lshift_and_v4i8_to(b, reg, bi_swz_v4i8(b, x3210), y, z);
+            I->op = ops[i];
+      });
+   }
+}