From fb73f0d11be96c26c5d471954c800cf94e3d4198 Mon Sep 17 00:00:00 2001
From: Eduard-Mihai Burtescu <eddyb@vectorware.com>
Date: Sun, 10 May 2026 20:41:38 +0300
Subject: [PATCH] [WIP] difftests: integrate `spirti` for emulating SPIR-V
 shaders on the CPU.

---
 tests/difftests/tests/Cargo.lock              | 666 +++++++++++++++++-
 tests/difftests/tests/Cargo.toml              |   3 +
 tests/difftests/tests/lib/Cargo.toml          |   1 +
 .../lib/src/scaffold/compute/wgpu_runner.rs   | 109 +++
 .../tests/lib/src/scaffold/shader/mod.rs      |   5 +
 .../src/scaffold/shader/rust_gpu_shader.rs    |   4 +
 6 files changed, 787 insertions(+), 1 deletion(-)

diff --git a/tests/difftests/tests/Cargo.lock b/tests/difftests/tests/Cargo.lock
index 32d5234f6d..199da5bc16 100644
--- a/tests/difftests/tests/Cargo.lock
+++ b/tests/difftests/tests/Cargo.lock
@@ -80,6 +80,24 @@ dependencies = [
  "memchr",
 ]
 
+[[package]]
+name = "aligned"
+version = "0.4.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ee4508988c62edf04abd8d92897fca0c2995d907ce1dfeaf369dac3716a40685"
+dependencies = [
+ "as-slice",
+]
+
+[[package]]
+name = "aligned-vec"
+version = "0.6.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "dc890384c8602f339876ded803c97ad529f3842aba97f6392b3dba0dd171769b"
+dependencies = [
+ "equator",
+]
+
 [[package]]
 name = "allocator-api2"
 version = "0.2.21"
@@ -107,6 +125,23 @@ version = "0.9.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d67af77d68a931ecd5cbd8a3b5987d63a1d1d1278f7f6a60ae33db485cdebb69"
 
+[[package]]
+name = "arbitrary"
+version = "1.4.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c3d036a3c4ab069c7b410a2ce876bd74808d2d0888a82667669f8e783a898bf1"
+
+[[package]]
+name = "arg_enum_proc_macro"
+version = "0.3.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0ae92a5119aa49cdbcf6b9f893fe4e1d98b04ccbf82ee0584ad948a44a734dea"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
 [[package]]
 name = "array_access-rust"
 version = "0.0.0"
@@ -130,6 +165,15 @@ version = "0.7.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "7c02d123df017efcdfbd739ef81735b36c5ba83ec3c59c80a9d7ecc718f92e50"
 
+[[package]]
+name = "as-slice"
+version = "0.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "516b6b4f0e40d50dcda9365d53964ec74560ad4284da2e7fc97122cd83174516"
+dependencies = [
+ "stable_deref_trait",
+]
+
 [[package]]
 name = "ash"
 version = "0.38.0+1.3.281"
@@ -162,6 +206,49 @@ version = "1.5.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "c08606f8c3cbf4ce6ec8e28fb0014a2c086708fe954eaa885384a6165172e7e8"
 
+[[package]]
+name = "av-scenechange"
+version = "0.14.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0f321d77c20e19b92c39e7471cf986812cbb46659d2af674adc4331ef3f18394"
+dependencies = [
+ "aligned",
+ "anyhow",
+ "arg_enum_proc_macro",
+ "arrayvec",
+ "log",
+ "num-rational",
+ "num-traits",
+ "pastey",
+ "rayon",
+ "thiserror",
+ "v_frame",
+ "y4m",
+]
+
+[[package]]
+name = "av1-grain"
+version = "0.2.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8cfddb07216410377231960af4fcab838eaa12e013417781b78bd95ee22077f8"
+dependencies = [
+ "anyhow",
+ "arrayvec",
+ "log",
+ "nom",
+ "num-rational",
+ "v_frame",
+]
+
+[[package]]
+name = "avif-serialize"
+version = "0.8.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e7178fe5f7d460b13895ebb9dcb28a3a6216d2df2574a0806cb51b555d297f38"
+dependencies = [
+ "arrayvec",
+]
+
 [[package]]
 name = "bit-set"
 version = "0.9.1"
@@ -177,6 +264,12 @@ version = "0.9.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b71798fca2c1fe1086445a7258a4bc81e6e49dcd24c8d0dd9a1e57395b603f51"
 
+[[package]]
+name = "bit_field"
+version = "0.10.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1e4b40c7323adcfc0a41c4b88143ed58346ff65a288fc144329c5c45e05d70c6"
+
 [[package]]
 name = "bitflags"
 version = "1.3.2"
@@ -192,6 +285,15 @@ dependencies = [
  "serde_core",
 ]
 
+[[package]]
+name = "bitstream-io"
+version = "4.10.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7eff00be299a18769011411c9def0d827e8f2d7bf0c3dbf53633147a8867fd1f"
+dependencies = [
+ "no_std_io2",
+]
+
 [[package]]
 name = "bitwise_ops-rust"
 version = "0.0.0"
@@ -232,6 +334,12 @@ dependencies = [
  "objc2",
 ]
 
+[[package]]
+name = "built"
+version = "0.8.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f4ad8f11f288f48ca24471bbd51ac257aaeaaa07adae295591266b792902ae64"
+
 [[package]]
 name = "bumpalo"
 version = "3.20.2"
@@ -258,6 +366,12 @@ dependencies = [
  "syn",
 ]
 
+[[package]]
+name = "byteorder-lite"
+version = "0.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8f1fe948ff07f4bd06c30984e69f5b4899c516a3ef74f34df92a2df2ab535495"
+
 [[package]]
 name = "camino"
 version = "1.2.2"
@@ -342,6 +456,12 @@ dependencies = [
  "unicode-width",
 ]
 
+[[package]]
+name = "color_quant"
+version = "1.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3d7b894f5411737b7867f4827955924d7c254fc9f4d91a6aad6b097804b1018b"
+
 [[package]]
 name = "const_fold_int-const-expr-cpu"
 version = "0.0.0"
@@ -444,6 +564,31 @@ dependencies = [
  "cfg-if",
 ]
 
+[[package]]
+name = "crossbeam-deque"
+version = "0.8.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9dd111b7b7f7d55b72c0a6ae361660ee5853c9af73f70c3c2ef6858b950e2e51"
+dependencies = [
+ "crossbeam-epoch",
+ "crossbeam-utils",
+]
+
+[[package]]
+name = "crossbeam-epoch"
+version = "0.9.18"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5b82ac4a3c2ca9c3460964f020e1402edd5753411d7737aa39c3714ad1b5420e"
+dependencies = [
+ "crossbeam-utils",
+]
+
+[[package]]
+name = "crossbeam-utils"
+version = "0.8.21"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d0a5c400df2834b80a4c3327b3aad3a4c4cd4de0629063962b03235697506a28"
+
 [[package]]
 name = "crunchy"
 version = "0.2.4"
@@ -475,6 +620,7 @@ dependencies = [
  "glam",
  "serde",
  "serde_json",
+ "spirti",
  "spirv-builder",
  "spirv-std",
  "tempfile",
@@ -537,6 +683,26 @@ dependencies = [
  "stable_deref_trait",
 ]
 
+[[package]]
+name = "equator"
+version = "0.4.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4711b213838dfee0117e3be6ac926007d7f433d7bbe33595975d4190cb07e6fc"
+dependencies = [
+ "equator-macro",
+]
+
+[[package]]
+name = "equator-macro"
+version = "0.4.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "44f23cf4b44bfce11a86ace86f8a73ffdec849c9fd00a386a53d278bd9e81fb3"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
 [[package]]
 name = "equivalent"
 version = "1.0.2"
@@ -564,6 +730,21 @@ dependencies = [
  "windows-sys",
 ]
 
+[[package]]
+name = "exr"
+version = "1.74.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4300e043a56aa2cb633c01af81ca8f699a321879a7854d3896a0ba89056363be"
+dependencies = [
+ "bit_field",
+ "half",
+ "lebe",
+ "miniz_oxide",
+ "rayon-core",
+ "smallvec",
+ "zune-inflate",
+]
+
 [[package]]
 name = "fallible-iterator"
 version = "0.3.0"
@@ -576,6 +757,21 @@ version = "2.4.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9f1f227452a390804cdb637b74a86990f2a7d7ba4b7d5693aac9b4dd6defd8d6"
 
+[[package]]
+name = "fax"
+version = "0.2.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "caf1079563223d5d59d83c85886a56e586cfd5c1a26292e971a0fa266531ac5a"
+
+[[package]]
+name = "fdeflate"
+version = "0.3.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1e6853b52649d4ac5c0bd02320cddc5ba956bdb407c4b75a2c6b75bf51500f8c"
+dependencies = [
+ "simd-adler32",
+]
+
 [[package]]
 name = "find-msvc-tools"
 version = "0.1.9"
@@ -732,6 +928,16 @@ dependencies = [
  "wasip3",
 ]
 
+[[package]]
+name = "gif"
+version = "0.14.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ee8cfcc411d9adbbaba82fb72661cc1bcca13e8bba98b364e62b2dba8f960159"
+dependencies = [
+ "color_quant",
+ "weezl",
+]
+
 [[package]]
 name = "gimli"
 version = "0.31.1"
@@ -946,6 +1152,46 @@ dependencies = [
  "icu_properties",
 ]
 
+[[package]]
+name = "image"
+version = "0.25.10"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "85ab80394333c02fe689eaf900ab500fbd0c2213da414687ebf995a65d5a6104"
+dependencies = [
+ "bytemuck",
+ "byteorder-lite",
+ "color_quant",
+ "exr",
+ "gif",
+ "image-webp",
+ "moxcms",
+ "num-traits",
+ "png",
+ "qoi",
+ "ravif",
+ "rayon",
+ "rgb",
+ "tiff",
+ "zune-core",
+ "zune-jpeg",
+]
+
+[[package]]
+name = "image-webp"
+version = "0.2.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "525e9ff3e1a4be2fbea1fdf0e98686a6d98b4d8f937e1bf7402245af1909e8c3"
+dependencies = [
+ "byteorder-lite",
+ "quick-error",
+]
+
+[[package]]
+name = "imgref"
+version = "1.12.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "40fac9d56ed6437b198fddba683305e8e2d651aa42647f00f5ae542e7f5c94a2"
+
 [[package]]
 name = "indexmap"
 version = "2.14.0"
@@ -964,6 +1210,17 @@ version = "0.2.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "969ee3fc68ec2e88eb21434ce4d9b7e1600d1ce92ff974560a6c4a304f5124b9"
 
+[[package]]
+name = "interpolate_name"
+version = "0.2.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c34819042dc3d3971c46c2190835914dfbe0c3c13f61449b2997f4e9722dfa60"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
 [[package]]
 name = "itertools"
 version = "0.10.5"
@@ -1022,12 +1279,28 @@ version = "0.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "09edd9e8b54e49e587e4f6295a7d29c3ea94d469cb40ab8ca70b288248a81db2"
 
+[[package]]
+name = "lebe"
+version = "0.5.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7a79a3332a6609480d7d0c9eab957bca6b455b91bb84e66d19f5ff66294b85b8"
+
 [[package]]
 name = "libc"
 version = "0.2.186"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "68ab91017fe16c622486840e4c83c9a37afeff978bd239b5293d61ece587de66"
 
+[[package]]
+name = "libfuzzer-sys"
+version = "0.4.12"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f12a681b7dd8ce12bff52488013ba614b869148d54dd79836ab85aafdd53f08d"
+dependencies = [
+ "arbitrary",
+ "cc",
+]
+
 [[package]]
 name = "libloading"
 version = "0.8.9"
@@ -1083,6 +1356,15 @@ version = "0.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b3bd0dd2cd90571056fdb71f6275fada10131182f84899f4b2a916e565d81d86"
 
+[[package]]
+name = "loop9"
+version = "0.1.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0fae87c125b03c1d2c0150c90365d7d6bcc53fb73a9acaef207d2d065860f062"
+dependencies = [
+ "imgref",
+]
+
 [[package]]
 name = "matchers"
 version = "0.2.0"
@@ -1126,6 +1408,16 @@ dependencies = [
  "difftest",
 ]
 
+[[package]]
+name = "maybe-rayon"
+version = "0.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8ea1f30cedd69f0a2954655f7188c6a834246d2bcf1e315e2ac40c4b24dc9519"
+dependencies = [
+ "cfg-if",
+ "rayon",
+]
+
 [[package]]
 name = "memchr"
 version = "2.8.0"
@@ -1157,6 +1449,16 @@ dependencies = [
  "simd-adler32",
 ]
 
+[[package]]
+name = "moxcms"
+version = "0.8.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bb85c154ba489f01b25c0d36ae69a87e4a1c73a72631fc6c0eb6dde34a73e44b"
+dependencies = [
+ "num-traits",
+ "pxfm",
+]
+
 [[package]]
 name = "naga"
 version = "29.0.1"
@@ -1184,6 +1486,36 @@ dependencies = [
  "unicode-ident",
 ]
 
+[[package]]
+name = "new_debug_unreachable"
+version = "1.0.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "650eef8c711430f1a879fdd01d4745a7deea475becfb90269c06775983bbf086"
+
+[[package]]
+name = "no_std_io2"
+version = "0.9.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "418abd1b6d34fbf6cae440dc874771b0525a604428704c76e48b29a5e67b8003"
+dependencies = [
+ "memchr",
+]
+
+[[package]]
+name = "nom"
+version = "8.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "df9761775871bdef83bee530e60050f7e54b1105350d6884eb0fb4f46c2f9405"
+dependencies = [
+ "memchr",
+]
+
+[[package]]
+name = "noop_proc_macro"
+version = "0.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0676bb32a98c1a483ce53e500a81ad9c3d5b3f7c920c28c24e9cb0980d0b5bc8"
+
 [[package]]
 name = "nu-ansi-term"
 version = "0.50.3"
@@ -1193,6 +1525,47 @@ dependencies = [
  "windows-sys",
 ]
 
+[[package]]
+name = "num-bigint"
+version = "0.4.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a5e44f723f1133c9deac646763579fdb3ac745e418f2a7af9cd0c431da1f20b9"
+dependencies = [
+ "num-integer",
+ "num-traits",
+]
+
+[[package]]
+name = "num-derive"
+version = "0.4.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ed3955f1a9c7c0c15e092f9c887db08b1fc683305fdf6eb6684f22555355e202"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
+[[package]]
+name = "num-integer"
+version = "0.1.46"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7969661fd2958a5cb096e56c8e1ad0444ac2bbcd0061bd28660485a44879858f"
+dependencies = [
+ "num-traits",
+]
+
+[[package]]
+name = "num-rational"
+version = "0.4.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f83d14da390562dca69fc84082e73e548e1ad308d24accdedd2720017cb37824"
+dependencies = [
+ "num-bigint",
+ "num-integer",
+ "num-traits",
+]
+
 [[package]]
 name = "num-traits"
 version = "0.2.19"
@@ -1360,6 +1733,18 @@ dependencies = [
  "windows-link",
 ]
 
+[[package]]
+name = "paste"
+version = "1.0.15"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "57c0d7b74b563b49d38dae00a0c37d4d6de9b432382b2892f0574ddcae73fd0a"
+
+[[package]]
+name = "pastey"
+version = "0.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "35fb2e5f958ec131621fdd531e9fc186ed768cbe395337403ae56c17a74c68ec"
+
 [[package]]
 name = "percent-encoding"
 version = "2.3.2"
@@ -1383,6 +1768,19 @@ version = "0.2.17"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "a89322df9ebe1c1578d689c92318e070967d1042b512afbe49518723f4e6d5cd"
 
+[[package]]
+name = "png"
+version = "0.18.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "60769b8b31b2a9f263dae2776c37b1b28ae246943cf719eb6946a1db05128a61"
+dependencies = [
+ "bitflags 2.11.1",
+ "crc32fast",
+ "fdeflate",
+ "flate2",
+ "miniz_oxide",
+]
+
 [[package]]
 name = "portable-atomic"
 version = "1.13.1"
@@ -1407,6 +1805,15 @@ dependencies = [
  "zerovec",
 ]
 
+[[package]]
+name = "ppv-lite86"
+version = "0.2.21"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "85eae3c4ed2f50dcfe72643da4befc30deadb458a9b590d720cde2f2b1e97da9"
+dependencies = [
+ "zerocopy",
+]
+
 [[package]]
 name = "presser"
 version = "0.3.1"
@@ -1437,6 +1844,19 @@ name = "profiling"
 version = "1.0.17"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "3eb8486b569e12e2c32ad3e204dbaba5e4b5b216e9367044f25f1dba42341773"
+dependencies = [
+ "profiling-procmacros",
+]
+
+[[package]]
+name = "profiling-procmacros"
+version = "1.0.18"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4488a4a36b9a4ba6b9334a32a39971f77c1436ec82c38707bce707699cc3bbcb"
+dependencies = [
+ "quote",
+ "syn",
+]
 
 [[package]]
 name = "push_constants-rust"
@@ -1455,6 +1875,27 @@ dependencies = [
  "difftest",
 ]
 
+[[package]]
+name = "pxfm"
+version = "0.1.29"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e0c5ccf5294c6ccd63a74f1565028353830a9c2f5eb0c682c355c471726a6e3f"
+
+[[package]]
+name = "qoi"
+version = "0.4.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7f6d64c71eb498fe9eae14ce4ec935c555749aef511cca85b5568910d6e48001"
+dependencies = [
+ "bytemuck",
+]
+
+[[package]]
+name = "quick-error"
+version = "2.0.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a993555f31e5a609f617c12db6250dedcac1b0a85076912c436e6fc9b2c8e6a3"
+
 [[package]]
 name = "quote"
 version = "1.0.45"
@@ -1476,6 +1917,85 @@ version = "6.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "f8dcc9c7d52a811697d2151c701e0d08956f92b0e24136cf4cf27b57a6a0d9bf"
 
+[[package]]
+name = "rand"
+version = "0.9.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "44c5af06bb1b7d3216d91932aed5265164bf384dc89cd6ba05cf59a35f5f76ea"
+dependencies = [
+ "rand_chacha",
+ "rand_core",
+]
+
+[[package]]
+name = "rand_chacha"
+version = "0.9.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d3022b5f1df60f26e1ffddd6c66e8aa15de382ae63b3a0c1bfc0e4d3e3f325cb"
+dependencies = [
+ "ppv-lite86",
+ "rand_core",
+]
+
+[[package]]
+name = "rand_core"
+version = "0.9.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "76afc826de14238e6e8c374ddcc1fa19e374fd8dd986b0d2af0d02377261d83c"
+dependencies = [
+ "getrandom 0.3.4",
+]
+
+[[package]]
+name = "rav1e"
+version = "0.8.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "43b6dd56e85d9483277cde964fd1bdb0428de4fec5ebba7540995639a21cb32b"
+dependencies = [
+ "aligned-vec",
+ "arbitrary",
+ "arg_enum_proc_macro",
+ "arrayvec",
+ "av-scenechange",
+ "av1-grain",
+ "bitstream-io",
+ "built",
+ "cfg-if",
+ "interpolate_name",
+ "itertools 0.14.0",
+ "libc",
+ "libfuzzer-sys",
+ "log",
+ "maybe-rayon",
+ "new_debug_unreachable",
+ "noop_proc_macro",
+ "num-derive",
+ "num-traits",
+ "paste",
+ "profiling",
+ "rand",
+ "rand_chacha",
+ "simd_helpers",
+ "thiserror",
+ "v_frame",
+ "wasm-bindgen",
+]
+
+[[package]]
+name = "ravif"
+version = "0.13.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e52310197d971b0f5be7fe6b57530dcd27beb35c1b013f29d66c1ad73fbbcc45"
+dependencies = [
+ "avif-serialize",
+ "imgref",
+ "loop9",
+ "quick-error",
+ "rav1e",
+ "rayon",
+ "rgb",
+]
+
 [[package]]
 name = "raw-string"
 version = "0.3.5"
@@ -1500,6 +2020,26 @@ dependencies = [
  "objc2-quartz-core",
 ]
 
+[[package]]
+name = "rayon"
+version = "1.12.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fb39b166781f92d482534ef4b4b1b2568f42613b53e5b6c160e24cfbfa30926d"
+dependencies = [
+ "either",
+ "rayon-core",
+]
+
+[[package]]
+name = "rayon-core"
+version = "1.13.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "22e18b0f0062d30d4230b2e85ff77fdfe4326feb054b9783a3460d8435c8ab91"
+dependencies = [
+ "crossbeam-deque",
+ "crossbeam-utils",
+]
+
 [[package]]
 name = "redox_syscall"
 version = "0.5.18"
@@ -1544,6 +2084,12 @@ version = "1.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "19b30a45b0cd0bcca8037f3d0dc3421eaf95327a17cad11964fb8179b4fc4832"
 
+[[package]]
+name = "rgb"
+version = "0.8.53"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "47b34b781b31e5d73e9fbc8689c70551fd1ade9a19e3e28cfec8580a79290cc4"
+
 [[package]]
 name = "rspirv"
 version = "0.12.0+sdk-1.3.268.0"
@@ -1566,6 +2112,16 @@ version = "1.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "08d43f7aa6b08d49f382cde6a7982047c3426db949b1424bc4b7ec9ae12c6ce2"
 
+[[package]]
+name = "rustc_apfloat"
+version = "0.2.3+llvm-462a31f5a5ab"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "486c2179b4796f65bfe2ee33679acf0927ac83ecf583ad6c91c3b4570911b9ad"
+dependencies = [
+ "bitflags 2.11.1",
+ "smallvec",
+]
+
 [[package]]
 name = "rustc_codegen_spirv"
 version = "0.10.0-alpha.1"
@@ -1588,7 +2144,7 @@ dependencies = [
  "rustix",
  "sanitize-filename",
  "smallvec",
- "spirt",
+ "spirt 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "spirv-std-types",
  "spirv-tools",
  "strum",
@@ -1767,6 +2323,15 @@ version = "0.3.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "703d5c7ef118737c72f1af64ad2f6f8c5e1921f818cdcb97b8fe6fc69bf66214"
 
+[[package]]
+name = "simd_helpers"
+version = "0.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "95890f873bec569a0362c235787f3aca6e1e887302ba4840839bcc6459c42da6"
+dependencies = [
+ "quote",
+]
+
 [[package]]
 name = "simple-compute-rust"
 version = "0.0.0"
@@ -1818,6 +2383,44 @@ dependencies = [
  "smallvec",
 ]
 
+[[package]]
+name = "spirt"
+version = "0.4.0"
+source = "git+https://github.com/Rust-GPU/spirt?branch=eddyb%2Fspirti#7e664801ece15c16068c3b5edd5fb00895217e24"
+dependencies = [
+ "arrayvec",
+ "bytemuck",
+ "derive_more",
+ "elsa",
+ "indexmap",
+ "internal-iterator",
+ "itertools 0.10.5",
+ "lazy_static",
+ "longest-increasing-subsequence",
+ "rustc-hash",
+ "rustc_apfloat",
+ "serde",
+ "serde_json",
+ "smallvec",
+]
+
+[[package]]
+name = "spirti"
+version = "0.1.0"
+source = "git+https://github.com/Rust-GPU/spirt?branch=eddyb%2Fspirti#7e664801ece15c16068c3b5edd5fb00895217e24"
+dependencies = [
+ "arrayvec",
+ "derive_more",
+ "image",
+ "indexmap",
+ "itertools 0.10.5",
+ "lazy_static",
+ "rayon",
+ "rustc-hash",
+ "smallvec",
+ "spirt 0.4.0 (git+https://github.com/Rust-GPU/spirt?branch=eddyb%2Fspirti)",
+]
+
 [[package]]
 name = "spirv"
 version = "0.3.0+sdk-1.3.268.0"
@@ -2017,6 +2620,20 @@ dependencies = [
  "cfg-if",
 ]
 
+[[package]]
+name = "tiff"
+version = "0.11.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b63feaf3343d35b6ca4d50483f94843803b0f51634937cc2ec519fc32232bc52"
+dependencies = [
+ "fax",
+ "flate2",
+ "half",
+ "quick-error",
+ "weezl",
+ "zune-jpeg",
+]
+
 [[package]]
 name = "tinystr"
 version = "0.8.3"
@@ -2238,6 +2855,17 @@ version = "1.0.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b6c140620e7ffbb22c2dee59cafe6084a59b5ffc27a8859a5f0d494b5d52b6be"
 
+[[package]]
+name = "v_frame"
+version = "0.3.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "666b7727c8875d6ab5db9533418d7c764233ac9c0cff1d469aec8fa127597be2"
+dependencies = [
+ "aligned-vec",
+ "num-traits",
+ "wasm-bindgen",
+]
+
 [[package]]
 name = "valuable"
 version = "0.1.1"
@@ -2425,6 +3053,12 @@ dependencies = [
  "wasm-bindgen",
 ]
 
+[[package]]
+name = "weezl"
+version = "0.1.12"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a28ac98ddc8b9274cb41bb4d9d4d5c425b6020c50c46f25559911905610b4a88"
+
 [[package]]
 name = "wgpu"
 version = "29.0.1"
@@ -2833,6 +3467,12 @@ version = "0.6.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "1ffae5123b2d3fc086436f8834ae3ab053a283cfac8fe0a0b8eaae044768a4c4"
 
+[[package]]
+name = "y4m"
+version = "0.8.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7a5a4b21e1a62b67a2970e6831bc091d7b87e119e7f9791aef9702e3bef04448"
+
 [[package]]
 name = "yoke"
 version = "0.8.2"
@@ -2935,3 +3575,27 @@ name = "zmij"
 version = "1.0.21"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b8848ee67ecc8aedbaf3e4122217aff892639231befc6a1b58d29fff4c2cabaa"
+
+[[package]]
+name = "zune-core"
+version = "0.5.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "cb8a0807f7c01457d0379ba880ba6322660448ddebc890ce29bb64da71fb40f9"
+
+[[package]]
+name = "zune-inflate"
+version = "0.2.54"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "73ab332fe2f6680068f3582b16a24f90ad7096d5d39b974d1c0aff0125116f02"
+dependencies = [
+ "simd-adler32",
+]
+
+[[package]]
+name = "zune-jpeg"
+version = "0.5.15"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "27bc9d5b815bc103f142aa054f561d9187d191692ec7c2d1e2b4737f8dbd7296"
+dependencies = [
+ "zune-core",
+]
diff --git a/tests/difftests/tests/Cargo.toml b/tests/difftests/tests/Cargo.toml
index dda56eb002..61e24d893e 100644
--- a/tests/difftests/tests/Cargo.toml
+++ b/tests/difftests/tests/Cargo.toml
@@ -100,3 +100,6 @@ codegen-units = 256
 #
 # rustflags = ["-Zshare-generics=off"]
 codegen-units = 1
+
+[profile.release.package."spirti"]
+opt-level = 0
diff --git a/tests/difftests/tests/lib/Cargo.toml b/tests/difftests/tests/lib/Cargo.toml
index ba40413508..faafa8b4fe 100644
--- a/tests/difftests/tests/lib/Cargo.toml
+++ b/tests/difftests/tests/lib/Cargo.toml
@@ -31,6 +31,7 @@ tempfile = "3.5"
 futures = "0.3.31"
 bytemuck = "1.21.0"
 anyhow = "1.0.98"
+spirti = { git = "https://github.com/Rust-GPU/spirt", branch = "eddyb/spirti" }
 
 [lints]
 workspace = true
diff --git a/tests/difftests/tests/lib/src/scaffold/compute/wgpu_runner.rs b/tests/difftests/tests/lib/src/scaffold/compute/wgpu_runner.rs
index c10af5c298..bbee3e6600 100644
--- a/tests/difftests/tests/lib/src/scaffold/compute/wgpu_runner.rs
+++ b/tests/difftests/tests/lib/src/scaffold/compute/wgpu_runner.rs
@@ -57,6 +57,115 @@ where
     }
 
     pub fn run(&self) -> anyhow::Result<Vec<Option<Vec<u8>>>> {
+        // HACK(eddyb) running the test via `spirti`, instead.
+        if std::env::var("DIFFTEST_SPIRTI").is_ok() {
+            if let Ok(Some((spv_bytes, spv_entry_name))) = self.shader.maybe_spirv_bytes() {
+                use spirti::spirt::{self, Context, ExportKey, Exportee, Module, spv};
+                use std::num::NonZeroU32;
+                use std::rc::Rc;
+
+                let wk = &spirti::SpvSpecWithExtras::get().well_known;
+
+                let mut module =
+                    Module::lower_from_spv_bytes(Rc::new(Context::new()), spv_bytes).unwrap();
+                spirt::passes::legalize::structurize_func_cfgs(&mut module);
+
+                let mut interpreter = spirti::Interpreter::new(
+                    &module,
+                    spirti::DebugOptions::from_env(),
+                    &spirt::mem::LayoutConfig::VULKAN_SCALAR_LAYOUT_LE,
+                );
+
+                let (_, entry_exec_model, entry) = module
+                    .exports
+                    .iter()
+                    .filter_map(|(export_key, exportee)| match (export_key, exportee) {
+                        (
+                            ExportKey::SpvEntryPoint {
+                                imms,
+                                interface_global_vars: _,
+                            },
+                            &Exportee::Func(func),
+                        ) => {
+                            let exec_model = match imms[0] {
+                                spv::Imm::Short(kind, exec_model) => {
+                                    assert_eq!(kind, wk.ExecutionModel);
+                                    exec_model
+                                }
+                                _ => unreachable!(),
+                            };
+                            let name = spv::extract_literal_string(&imms[1..]).unwrap();
+
+                            Some((name, exec_model, func))
+                        }
+                        _ => None,
+                    })
+                    .find(|(name, _, _)| *name == spv_entry_name)
+                    .unwrap();
+
+                assert!(entry_exec_model == wk.GLCompute);
+                let entry_local_size = match interpreter.get_spv_attr(
+                    module.funcs[entry].attrs,
+                    wk.OpExecutionMode,
+                    wk.ExecutionMode,
+                    wk.LocalSize,
+                ) {
+                    Some(&[x, y, z]) => [x, y, z].map(|x| match x {
+                        spv::Imm::Short(_, x) => x,
+                        _ => unreachable!(),
+                    }),
+                    _ => unreachable!(),
+                };
+
+                for (i, buffer_config) in self.buffers.iter().enumerate() {
+                    let slot = match buffer_config.usage {
+                        // FIXME(eddyb) consider informing `spirti` about read-only buffers.
+                        BufferUsage::Storage | BufferUsage::StorageReadOnly => {
+                            spirti::BindSlot::StorageBuffer {
+                                descriptor_set: 0,
+                                binding: i as u32,
+                            }
+                        }
+                        BufferUsage::Uniform => todo!(),
+                    };
+                    interpreter.bind_memory(
+                        slot,
+                        buffer_config.initial_data.clone().unwrap_or_else(|| {
+                            // FIXME(eddyb) might be better to treat this as `undef`.
+                            vec![0; buffer_config.size as usize]
+                        }),
+                    );
+                }
+
+                if let Some(push_constant_bytes) = self.push_constant.clone() {
+                    interpreter.bind_memory(spirti::BindSlot::PushConstant, push_constant_bytes);
+                }
+
+                interpreter.launch = Some(spirti::Launch::Compute {
+                    local: entry_local_size.map(|x| NonZeroU32::new(x).unwrap()),
+                    global: self.dispatch.map(|x| NonZeroU32::new(x).unwrap()),
+                });
+                interpreter.eval_call(entry, [].into_iter().collect());
+
+                return Ok(self
+                    .buffers
+                    .iter()
+                    .enumerate()
+                    .map(|(i, buffer_config)| {
+                        matches!(buffer_config.usage, BufferUsage::Storage).then(|| {
+                            interpreter
+                                .read_bound_memory(spirti::BindSlot::StorageBuffer {
+                                    descriptor_set: 0,
+                                    binding: i as u32,
+                                })
+                                .ok()
+                                .unwrap()
+                        })
+                    })
+                    .collect());
+            }
+        }
+
         let instance = wgpu::Instance::new(wgpu::InstanceDescriptor::new_without_display_handle());
         let adapter = block_on(instance.request_adapter(&wgpu::RequestAdapterOptions {
             power_preference: wgpu::PowerPreference::HighPerformance,
diff --git a/tests/difftests/tests/lib/src/scaffold/shader/mod.rs b/tests/difftests/tests/lib/src/scaffold/shader/mod.rs
index 53c0c8ac20..2290ff8ed8 100644
--- a/tests/difftests/tests/lib/src/scaffold/shader/mod.rs
+++ b/tests/difftests/tests/lib/src/scaffold/shader/mod.rs
@@ -18,4 +18,9 @@ pub trait WgpuShader {
         device: &wgpu::Device,
         pipeline_layout: &wgpu::PipelineLayout,
     ) -> anyhow::Result<wgpu::ComputePipeline>;
+
+    // HACK(eddyb) used for hooking `spirti` into `wgpu_runner`.
+    fn maybe_spirv_bytes(&self) -> anyhow::Result<Option<(Vec<u8>, String)>> {
+        Ok(None)
+    }
 }
diff --git a/tests/difftests/tests/lib/src/scaffold/shader/rust_gpu_shader.rs b/tests/difftests/tests/lib/src/scaffold/shader/rust_gpu_shader.rs
index bac09d2e14..55e6c31bb1 100644
--- a/tests/difftests/tests/lib/src/scaffold/shader/rust_gpu_shader.rs
+++ b/tests/difftests/tests/lib/src/scaffold/shader/rust_gpu_shader.rs
@@ -110,6 +110,10 @@ impl WgpuShader for RustComputeShader {
         });
         Ok(pipeline)
     }
+
+    fn maybe_spirv_bytes(&self) -> anyhow::Result<Option<(Vec<u8>, String)>> {
+        Ok(Some(self.spirv_bytes()?))
+    }
 }
 
 /// For the SPIR-V shader, the manifest directory is used as the build path.