Stream: git-wasmtime

Topic: wasmtime / issue #7465 Cranelift: Fix union node bitpacking

view this post on Zulip Wasmtime GitHub notifications bot (Nov 03 2023 at 15:59):

cfallin commented on issue #7465:

Last merge-queue test run seemed to show a real assert failure during compilation:

thread '<unnamed>' panicked at 'assertion failed: x < (1 << bits)', cranelift/codegen/src/ir/dfg.rs:557:9

weird that it only reproduces on the MSRV run and for an integration test?

view this post on Zulip Wasmtime GitHub notifications bot (Nov 03 2023 at 16:03):

alexcrichton commented on issue #7465:

I'm going to remove from the queue due to ^

view this post on Zulip Wasmtime GitHub notifications bot (Nov 03 2023 at 16:04):

fitzgen commented on issue #7465:

It looks like we are creating a union of two values and the values' indices don't fit in the packed representation

view this post on Zulip Wasmtime GitHub notifications bot (Nov 03 2023 at 16:16):

fitzgen commented on issue #7465:

Does anyone know how to run the tokio example, or at least build the wasms that it uses?

cargo build --target wasm32-wasi inside examples/tokio/wasm doesn't seem to actually produce any wasm files for me.

view this post on Zulip Wasmtime GitHub notifications bot (Nov 03 2023 at 16:20):

alexcrichton commented on issue #7465:

cargo build --target wasm32-wasi --manifest-path examples/tokio/wasm/Cargo.toml
cargo run --example tokio --features wasmtime-wasi/tokio

view this post on Zulip Wasmtime GitHub notifications bot (Nov 03 2023 at 18:14):

fitzgen commented on issue #7465:

Hm I can't reproduce the assertion failure for that example.

But I did find an off-by-one bug in the assertion. It allows 0x00ff_ffff to be encoded as-is but that conflicts with the sentinal we use to represent 0xffff_ffff. Tweaked to fix the assertion.

view this post on Zulip Wasmtime GitHub notifications bot (Nov 03 2023 at 18:15):

fitzgen edited a comment on issue #7465:

Hm I can't reproduce the assertion failure for that example.

But I did find an off-by-one bug in the assertion. It allows 0x0000_0fff to be encoded as-is but that conflicts with the sentinal we use to represent 0xffff_ffff. Tweaked to fix the assertion.

view this post on Zulip Wasmtime GitHub notifications bot (Nov 03 2023 at 18:30):

fitzgen commented on issue #7465:

Okay I was able to repro with the 1.71.0 toolchain. Interestingly enough, it seemed to hang for a while before actually panicking, when the other toolchains ran to completion almost immediately.

view this post on Zulip Wasmtime GitHub notifications bot (Nov 03 2023 at 19:14):

fitzgen commented on issue #7465:

Still going (it is generating a lot of output) but it looks like we've gone into some kind of loop where we are unioning values like x, x+1, x+2, .... Since this only shows up on 1.71.0, I'm thinking this might be a miscompile in rustc/llvm?

FITZGEN: packing union(tag = 11, ty = 79, x = 0xe90db0, y = 0xc29cf9)
FITZGEN: packing union(tag = 11, ty = 79, x = 0xe90db1, y = 0xc29cf9)
FITZGEN: packing union(tag = 11, ty = 79, x = 0xe90db2, y = 0xc29cf9)
FITZGEN: packing union(tag = 11, ty = 79, x = 0xe90db3, y = 0xc29cf9)
FITZGEN: packing union(tag = 11, ty = 79, x = 0xe90db4, y = 0xc29cf9)
FITZGEN: packing union(tag = 11, ty = 79, x = 0xe90db5, y = 0xc29d09)
FITZGEN: packing union(tag = 11, ty = 79, x = 0xe90db6, y = 0xc29cf9)
FITZGEN: packing union(tag = 11, ty = 79, x = 0xe90db7, y = 0xc29cf9)
FITZGEN: packing union(tag = 11, ty = 79, x = 0xe90db8, y = 0xc29cf9)
FITZGEN: packing union(tag = 11, ty = 79, x = 0xe90db9, y = 0xc29d09)
FITZGEN: packing union(tag = 11, ty = 79, x = 0xe90dba, y = 0xc29cf9)
FITZGEN: packing union(tag = 11, ty = 79, x = 0xe90dbb, y = 0xc29d1f)
FITZGEN: packing union(tag = 11, ty = 79, x = 0xe90dbc, y = 0xc29cf9)
FITZGEN: packing union(tag = 11, ty = 79, x = 0xe90dbd, y = 0xc29cf9)
FITZGEN: packing union(tag = 11, ty = 79, x = 0xe90dbe, y = 0xc29d09)
FITZGEN: packing union(tag = 11, ty = 79, x = 0xe90dbf, y = 0xc29cf9)
FITZGEN: packing union(tag = 11, ty = 79, x = 0xe90dc0, y = 0xc29cf9)
FITZGEN: packing union(tag = 11, ty = 79, x = 0xe90dc1, y = 0xc29cf9)
FITZGEN: packing union(tag = 11, ty = 79, x = 0xe90dc2, y = 0xc29cf9)
FITZGEN: packing union(tag = 11, ty = 79, x = 0xe90dc3, y = 0xc29d09)

view this post on Zulip Wasmtime GitHub notifications bot (Nov 03 2023 at 19:15):

fitzgen commented on issue #7465:

Yep, it just finished:

FITZGEN: packing union(tag = 11, ty = 79, x = 0xfffff9, y = 0xc29cf9)
FITZGEN: packing union(tag = 11, ty = 79, x = 0xfffffa, y = 0xc29cf9)
FITZGEN: packing union(tag = 11, ty = 79, x = 0xfffffb, y = 0xc29cf9)
FITZGEN: packing union(tag = 11, ty = 79, x = 0xfffffc, y = 0xc29cf9)
FITZGEN: packing union(tag = 11, ty = 79, x = 0xfffffd, y = 0xc29cf9)
FITZGEN: packing union(tag = 11, ty = 79, x = 0xfffffe, y = 0xc29d09)
FITZGEN: packing union(tag = 11, ty = 79, x = 0xffffff, y = 0xc29cf9)
thread '<unnamed>' panicked at '16777215 does not fit into 24 bits (must be less than 16777215 to allow for a 0xffffffff sentinal)', cranelift/codegen/src/ir/dfg.rs:558:9
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

view this post on Zulip Wasmtime GitHub notifications bot (Nov 03 2023 at 20:25):

fitzgen edited a comment on issue #7465:

Hm I can't reproduce the assertion failure for that example.

But I did find an off-by-one bug in the assertion. It allows 0x00ff_ffff to be encoded as-is but that conflicts with the sentinal we use to represent 0xffff_ffff. Tweaked to fix the assertion.

view this post on Zulip Wasmtime GitHub notifications bot (Nov 04 2023 at 01:03):

github-actions[bot] commented on issue #7465:

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cc @cfallin, @fitzgen

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view this post on Zulip Wasmtime GitHub notifications bot (Nov 06 2023 at 17:34):

fitzgen commented on issue #7465:

I can't reproduce the test failure in CI. I'm also on linux x64 and using rust 1.73. Not sure what is up here.

view this post on Zulip Wasmtime GitHub notifications bot (Nov 07 2023 at 09:35):

afonso360 commented on issue #7465:

Hey, I ran the fuzzer on RISC-V overnight on this branch, to check if there is something wrong with the RISC-V backend. I don't know if there is yet, but I think I got a reproduction of the issue that was happening in CI earlier.

<details>
<summary>Testcase</summary>

;; Run test case

test interpret
test run
set opt_level=speed_and_size
target riscv64gc has_zca has_zcd

function %a(i8 sext, i16, i64 sext, i128 uext, i64, i128 uext, i64 uext, i64 uext, i64 uext, i128 uext, i32 sext, f64, i64 sext) -> i8 fast {
    ss0 = explicit_slot 29
    ss1 = explicit_slot 17
    ss2 = explicit_slot 49
    ss3 = explicit_slot 52
    ss4 = explicit_slot 17
    ss5 = explicit_slot 17

block0(v0: i8, v1: i16, v2: i64, v3: i128, v4: i64, v5: i128, v6: i64, v7: i64, v8: i64, v9: i128, v10: i32, v11: f64, v12: i64):
    v54 -> v1
    v37 = rotl v0, v10
    v38 = rotl v37, v10
    v39 = rotl v38, v10
    v40 = rotl v39, v10
    v41 = rotl v40, v10
    v42 = rotl v41, v10
    v43 = select_spectre_guard v1, v10, v10
    v44 = bxor_not v43, v43
    v55 -> v44
    v45 = bitrev v42
    v46 = sextend.i128 v45
    v47 = rotl v45, v44
    v48 = rotl v47, v44
    v49 = select v48, v48, v48
    v50 = rotl v49, v44
    v51 = rotl v50, v44
    v52 = rotl v51, v44
    v53 = rotl v52, v44
    v58 -> v53
    v56 = select_spectre_guard.i32 v54, v55, v55
    v57 = bxor_not v56, v56
    v59 = bitrev.i8 v58
    v61 = rotl v59, v57
    v62 = rotl v61, v57
    v63 = select v62, v62, v62
    v64 = rotl v63, v57
    v65 = rotl v64, v57
    v66 = rotl v65, v57
    v67 = rotl v66, v57
    v68 = rotr v67, v54
    v69 = rotl v68, v57
    v70 = rotl v69, v57
    v71 = rotl v70, v57
    v72 = rotl v71, v57
    v73 = rotl v72, v57
    return v73
}

; run: %a(17, 4474, 4803839602528529, -10005959247738946646150328352768, 19070975, 281564249487374563584566874706289408, 8440, 0, 0, 0, 0, 0.0, 0) == 34

</details>

<details>
<summary>Egraphs Result main</summary>

function %a(i8 sext, i16, i64 sext, i128 uext, i64, i128 uext, i64 uext, i64 uext, i64 uext, i128 uext, i32 sext, f64, i64 sext) -> i8 fast {
block0(v0: i8, v1: i16, v2: i64, v3: i128, v4: i64, v5: i128, v6: i64, v7: i64, v8: i64, v9: i128, v10: i32, v11: f64, v12: i64):
    v43 = select_spectre_guard v1, v10, v10
    v91 = iconst.i32 0xffff_ffff
    v56 = select_spectre_guard v1, v91, v91  ; v91 = 0xffff_ffff, v91 = 0xffff_ffff
    v76 = iadd v10, v10
    v79 = iadd v76, v10
    v82 = iadd v79, v10
    v85 = iadd v82, v10
    v88 = iadd v85, v10
    v89 = rotl v0, v88
    v45 = bitrev v89
    v215 = iconst.i32 2
    v217 = rotl v45, v215  ; v215 = 2
    v59 = bitrev v217
    v308 = uextend.i32 v1
    v310 = isub v308, v215  ; v215 = 2
    v311 = ineg v310
    v404 = iconst.i32 0xffff_fffb
    v406 = iadd v311, v404  ; v404 = 0xffff_fffb
    v408 = rotl v59, v406
    return v408
}

</details>

<details>
<summary>Egraphs Result fix-egraph-union</summary>

function %a(i8 sext, i16, i64 sext, i128 uext, i64, i128 uext, i64 uext, i64 uext, i64 uext, i128 uext, i32 sext, f64, i64 sext) -> i8 fast {
block0(v0: i8, v1: i16, v2: i64, v3: i128, v4: i64, v5: i128, v6: i64, v7: i64, v8: i64, v9: i128, v10: i32, v11: f64, v12: i64):
    v43 = select_spectre_guard v1, v10, v10
    v251 = iconst.i32 0xffff_ffff
    v56 = select_spectre_guard v1, v251, v251  ; v251 = 0xffff_ffff, v251 = 0xffff_ffff
    v76 = iadd v10, v10
    v79 = iadd v76, v10
    v93 = iadd v79, v10
    v130 = iadd v10, v93
    v176 = iadd v10, v130
    v177 = rotl v0, v176
    v45 = bitrev v177
    v679 = iconst.i32 10
    v681 = rotl v45, v679  ; v679 = 10
    v59 = bitrev v681
    v376 = iconst.i32 0xffff_fffd
    v1116 = uextend.i32 v1
    v1161 = isub v376, v1116  ; v376 = 0xffff_fffd
    v1936 = rotl v59, v1161
    return v1936
}

</details>

This testcase spends a huge amount of time in egraphs with this PR and it now fails where it didn't before. Although I'm not 100% sure this isn't a bug in one of the rules that wasn't discovered previously.

I'm going to look into this again later today

view this post on Zulip Wasmtime GitHub notifications bot (Nov 07 2023 at 09:37):

afonso360 edited a comment on issue #7465:

Hey, I ran the fuzzer on RISC-V overnight on this branch to check if there is something wrong with the RISC-V backend. I don't know if there is yet, but I think I got a reproduction of the issue that was happening in CI earlier.

<details>
<summary>Testcase</summary>

;; Run test case

test interpret
test run
set opt_level=speed_and_size
target riscv64gc has_zca has_zcd

function %a(i8 sext, i16, i64 sext, i128 uext, i64, i128 uext, i64 uext, i64 uext, i64 uext, i128 uext, i32 sext, f64, i64 sext) -> i8 fast {
    ss0 = explicit_slot 29
    ss1 = explicit_slot 17
    ss2 = explicit_slot 49
    ss3 = explicit_slot 52
    ss4 = explicit_slot 17
    ss5 = explicit_slot 17

block0(v0: i8, v1: i16, v2: i64, v3: i128, v4: i64, v5: i128, v6: i64, v7: i64, v8: i64, v9: i128, v10: i32, v11: f64, v12: i64):
    v54 -> v1
    v37 = rotl v0, v10
    v38 = rotl v37, v10
    v39 = rotl v38, v10
    v40 = rotl v39, v10
    v41 = rotl v40, v10
    v42 = rotl v41, v10
    v43 = select_spectre_guard v1, v10, v10
    v44 = bxor_not v43, v43
    v55 -> v44
    v45 = bitrev v42
    v46 = sextend.i128 v45
    v47 = rotl v45, v44
    v48 = rotl v47, v44
    v49 = select v48, v48, v48
    v50 = rotl v49, v44
    v51 = rotl v50, v44
    v52 = rotl v51, v44
    v53 = rotl v52, v44
    v58 -> v53
    v56 = select_spectre_guard.i32 v54, v55, v55
    v57 = bxor_not v56, v56
    v59 = bitrev.i8 v58
    v61 = rotl v59, v57
    v62 = rotl v61, v57
    v63 = select v62, v62, v62
    v64 = rotl v63, v57
    v65 = rotl v64, v57
    v66 = rotl v65, v57
    v67 = rotl v66, v57
    v68 = rotr v67, v54
    v69 = rotl v68, v57
    v70 = rotl v69, v57
    v71 = rotl v70, v57
    v72 = rotl v71, v57
    v73 = rotl v72, v57
    return v73
}

; run: %a(17, 4474, 4803839602528529, -10005959247738946646150328352768, 19070975, 281564249487374563584566874706289408, 8440, 0, 0, 0, 0, 0.0, 0) == 34

</details>

<details>
<summary>Egraphs Result main</summary>

function %a(i8 sext, i16, i64 sext, i128 uext, i64, i128 uext, i64 uext, i64 uext, i64 uext, i128 uext, i32 sext, f64, i64 sext) -> i8 fast {
block0(v0: i8, v1: i16, v2: i64, v3: i128, v4: i64, v5: i128, v6: i64, v7: i64, v8: i64, v9: i128, v10: i32, v11: f64, v12: i64):
    v43 = select_spectre_guard v1, v10, v10
    v91 = iconst.i32 0xffff_ffff
    v56 = select_spectre_guard v1, v91, v91  ; v91 = 0xffff_ffff, v91 = 0xffff_ffff
    v76 = iadd v10, v10
    v79 = iadd v76, v10
    v82 = iadd v79, v10
    v85 = iadd v82, v10
    v88 = iadd v85, v10
    v89 = rotl v0, v88
    v45 = bitrev v89
    v215 = iconst.i32 2
    v217 = rotl v45, v215  ; v215 = 2
    v59 = bitrev v217
    v308 = uextend.i32 v1
    v310 = isub v308, v215  ; v215 = 2
    v311 = ineg v310
    v404 = iconst.i32 0xffff_fffb
    v406 = iadd v311, v404  ; v404 = 0xffff_fffb
    v408 = rotl v59, v406
    return v408
}

</details>

<details>
<summary>Egraphs Result fix-egraph-union</summary>

function %a(i8 sext, i16, i64 sext, i128 uext, i64, i128 uext, i64 uext, i64 uext, i64 uext, i128 uext, i32 sext, f64, i64 sext) -> i8 fast {
block0(v0: i8, v1: i16, v2: i64, v3: i128, v4: i64, v5: i128, v6: i64, v7: i64, v8: i64, v9: i128, v10: i32, v11: f64, v12: i64):
    v43 = select_spectre_guard v1, v10, v10
    v251 = iconst.i32 0xffff_ffff
    v56 = select_spectre_guard v1, v251, v251  ; v251 = 0xffff_ffff, v251 = 0xffff_ffff
    v76 = iadd v10, v10
    v79 = iadd v76, v10
    v93 = iadd v79, v10
    v130 = iadd v10, v93
    v176 = iadd v10, v130
    v177 = rotl v0, v176
    v45 = bitrev v177
    v679 = iconst.i32 10
    v681 = rotl v45, v679  ; v679 = 10
    v59 = bitrev v681
    v376 = iconst.i32 0xffff_fffd
    v1116 = uextend.i32 v1
    v1161 = isub v376, v1116  ; v376 = 0xffff_fffd
    v1936 = rotl v59, v1161
    return v1936
}

</details>

This testcase spends a huge amount of time in egraphs with this PR and it now fails where it didn't before. Although I'm not 100% sure this isn't a bug in one of the rules that wasn't discovered previously.

I'm going to look into this again later today

view this post on Zulip Wasmtime GitHub notifications bot (Nov 07 2023 at 10:44):

afonso360 edited a comment on issue #7465:

Hey, I ran the fuzzer on RISC-V overnight on this branch to check if there is something wrong with the RISC-V backend. I don't know if there is yet, but I think I got a reproduction of the issue that was happening in CI earlier.

<details>
<summary>Testcase</summary>

;; Run test case

test interpret
test run
set opt_level=speed_and_size
target riscv64gc has_zca has_zcd

function %a(i8 sext, i16, i64 sext, i128 uext, i64, i128 uext, i64 uext, i64 uext, i64 uext, i128 uext, i32 sext, f64, i64 sext) -> i8 fast {
    ss0 = explicit_slot 29
    ss1 = explicit_slot 17
    ss2 = explicit_slot 49
    ss3 = explicit_slot 52
    ss4 = explicit_slot 17
    ss5 = explicit_slot 17

block0(v0: i8, v1: i16, v2: i64, v3: i128, v4: i64, v5: i128, v6: i64, v7: i64, v8: i64, v9: i128, v10: i32, v11: f64, v12: i64):
    v54 -> v1
    v37 = rotl v0, v10
    v38 = rotl v37, v10
    v39 = rotl v38, v10
    v40 = rotl v39, v10
    v41 = rotl v40, v10
    v42 = rotl v41, v10
    v43 = select_spectre_guard v1, v10, v10
    v44 = bxor_not v43, v43
    v55 -> v44
    v45 = bitrev v42
    v46 = sextend.i128 v45
    v47 = rotl v45, v44
    v48 = rotl v47, v44
    v49 = select v48, v48, v48
    v50 = rotl v49, v44
    v51 = rotl v50, v44
    v52 = rotl v51, v44
    v53 = rotl v52, v44
    v58 -> v53
    v56 = select_spectre_guard.i32 v54, v55, v55
    v57 = bxor_not v56, v56
    v59 = bitrev.i8 v58
    v61 = rotl v59, v57
    v62 = rotl v61, v57
    v63 = select v62, v62, v62
    v64 = rotl v63, v57
    v65 = rotl v64, v57
    v66 = rotl v65, v57
    v67 = rotl v66, v57
    v68 = rotr v67, v54
    v69 = rotl v68, v57
    v70 = rotl v69, v57
    v71 = rotl v70, v57
    v72 = rotl v71, v57
    v73 = rotl v72, v57
    return v73
}

; run: %a(17, 4474, 4803839602528529, -10005959247738946646150328352768, 19070975, 281564249487374563584566874706289408, 8440, 0, 0, 0, 0, 0.0, 0) == 34

</details>

<details>
<summary>Egraphs Result main</summary>

function %a(i8 sext, i16, i64 sext, i128 uext, i64, i128 uext, i64 uext, i64 uext, i64 uext, i128 uext, i32 sext, f64, i64 sext) -> i8 fast {
block0(v0: i8, v1: i16, v2: i64, v3: i128, v4: i64, v5: i128, v6: i64, v7: i64, v8: i64, v9: i128, v10: i32, v11: f64, v12: i64):
    v43 = select_spectre_guard v1, v10, v10
    v91 = iconst.i32 0xffff_ffff
    v56 = select_spectre_guard v1, v91, v91  ; v91 = 0xffff_ffff, v91 = 0xffff_ffff
    v76 = iadd v10, v10
    v79 = iadd v76, v10
    v82 = iadd v79, v10
    v85 = iadd v82, v10
    v88 = iadd v85, v10
    v89 = rotl v0, v88
    v45 = bitrev v89
    v215 = iconst.i32 2
    v217 = rotl v45, v215  ; v215 = 2
    v59 = bitrev v217
    v308 = uextend.i32 v1
    v310 = isub v308, v215  ; v215 = 2
    v311 = ineg v310
    v404 = iconst.i32 0xffff_fffb
    v406 = iadd v311, v404  ; v404 = 0xffff_fffb
    v408 = rotl v59, v406
    return v408
}

</details>

<details>
<summary>Egraphs Result fix-egraph-union</summary>

function %a(i8 sext, i16, i64 sext, i128 uext, i64, i128 uext, i64 uext, i64 uext, i64 uext, i128 uext, i32 sext, f64, i64 sext) -> i8 fast {
block0(v0: i8, v1: i16, v2: i64, v3: i128, v4: i64, v5: i128, v6: i64, v7: i64, v8: i64, v9: i128, v10: i32, v11: f64, v12: i64):
    v43 = select_spectre_guard v1, v10, v10
    v251 = iconst.i32 0xffff_ffff
    v56 = select_spectre_guard v1, v251, v251  ; v251 = 0xffff_ffff, v251 = 0xffff_ffff
    v76 = iadd v10, v10
    v79 = iadd v76, v10
    v93 = iadd v79, v10
    v130 = iadd v10, v93
    v176 = iadd v10, v130
    v177 = rotl v0, v176
    v45 = bitrev v177
    v679 = iconst.i32 10
    v681 = rotl v45, v679  ; v679 = 10
    v59 = bitrev v681
    v376 = iconst.i32 0xffff_fffd
    v1116 = uextend.i32 v1
    v1161 = isub v376, v1116  ; v376 = 0xffff_fffd
    v1936 = rotl v59, v1161
    return v1936
}

</details>

~This testcase spends a huge amount of time in egraphs with this PR and it now fails where it didn't before. Although I'm not 100% sure this isn't a bug in one of the rules that wasn't discovered previously.~

~I'm going to look into this again later today~

Edit: This ended up being a RISC-V bug, but I think it's still worth looking at the testcase, we now spend a bunch of time building values which I'm not sure is intended.

view this post on Zulip Wasmtime GitHub notifications bot (Nov 07 2023 at 10:45):

afonso360 edited a comment on issue #7465:

Hey, I ran the fuzzer on RISC-V overnight on this branch to check if there is something wrong with the RISC-V backend. I don't know if there is yet, but I think I got a reproduction of the issue that was happening in CI earlier.

<details>
<summary>Testcase</summary>

;; Run test case

test interpret
test run
set opt_level=speed_and_size
target riscv64gc has_zca has_zcd

function %a(i8 sext, i16, i64 sext, i128 uext, i64, i128 uext, i64 uext, i64 uext, i64 uext, i128 uext, i32 sext, f64, i64 sext) -> i8 fast {
    ss0 = explicit_slot 29
    ss1 = explicit_slot 17
    ss2 = explicit_slot 49
    ss3 = explicit_slot 52
    ss4 = explicit_slot 17
    ss5 = explicit_slot 17

block0(v0: i8, v1: i16, v2: i64, v3: i128, v4: i64, v5: i128, v6: i64, v7: i64, v8: i64, v9: i128, v10: i32, v11: f64, v12: i64):
    v54 -> v1
    v37 = rotl v0, v10
    v38 = rotl v37, v10
    v39 = rotl v38, v10
    v40 = rotl v39, v10
    v41 = rotl v40, v10
    v42 = rotl v41, v10
    v43 = select_spectre_guard v1, v10, v10
    v44 = bxor_not v43, v43
    v55 -> v44
    v45 = bitrev v42
    v46 = sextend.i128 v45
    v47 = rotl v45, v44
    v48 = rotl v47, v44
    v49 = select v48, v48, v48
    v50 = rotl v49, v44
    v51 = rotl v50, v44
    v52 = rotl v51, v44
    v53 = rotl v52, v44
    v58 -> v53
    v56 = select_spectre_guard.i32 v54, v55, v55
    v57 = bxor_not v56, v56
    v59 = bitrev.i8 v58
    v61 = rotl v59, v57
    v62 = rotl v61, v57
    v63 = select v62, v62, v62
    v64 = rotl v63, v57
    v65 = rotl v64, v57
    v66 = rotl v65, v57
    v67 = rotl v66, v57
    v68 = rotr v67, v54
    v69 = rotl v68, v57
    v70 = rotl v69, v57
    v71 = rotl v70, v57
    v72 = rotl v71, v57
    v73 = rotl v72, v57
    return v73
}

; run: %a(17, 4474, 4803839602528529, -10005959247738946646150328352768, 19070975, 281564249487374563584566874706289408, 8440, 0, 0, 0, 0, 0.0, 0) == 34

</details>

<details>
<summary>Egraphs Result main</summary>

function %a(i8 sext, i16, i64 sext, i128 uext, i64, i128 uext, i64 uext, i64 uext, i64 uext, i128 uext, i32 sext, f64, i64 sext) -> i8 fast {
block0(v0: i8, v1: i16, v2: i64, v3: i128, v4: i64, v5: i128, v6: i64, v7: i64, v8: i64, v9: i128, v10: i32, v11: f64, v12: i64):
    v43 = select_spectre_guard v1, v10, v10
    v91 = iconst.i32 0xffff_ffff
    v56 = select_spectre_guard v1, v91, v91  ; v91 = 0xffff_ffff, v91 = 0xffff_ffff
    v76 = iadd v10, v10
    v79 = iadd v76, v10
    v82 = iadd v79, v10
    v85 = iadd v82, v10
    v88 = iadd v85, v10
    v89 = rotl v0, v88
    v45 = bitrev v89
    v215 = iconst.i32 2
    v217 = rotl v45, v215  ; v215 = 2
    v59 = bitrev v217
    v308 = uextend.i32 v1
    v310 = isub v308, v215  ; v215 = 2
    v311 = ineg v310
    v404 = iconst.i32 0xffff_fffb
    v406 = iadd v311, v404  ; v404 = 0xffff_fffb
    v408 = rotl v59, v406
    return v408
}

</details>

<details>
<summary>Egraphs Result fix-egraph-union</summary>

function %a(i8 sext, i16, i64 sext, i128 uext, i64, i128 uext, i64 uext, i64 uext, i64 uext, i128 uext, i32 sext, f64, i64 sext) -> i8 fast {
block0(v0: i8, v1: i16, v2: i64, v3: i128, v4: i64, v5: i128, v6: i64, v7: i64, v8: i64, v9: i128, v10: i32, v11: f64, v12: i64):
    v43 = select_spectre_guard v1, v10, v10
    v251 = iconst.i32 0xffff_ffff
    v56 = select_spectre_guard v1, v251, v251  ; v251 = 0xffff_ffff, v251 = 0xffff_ffff
    v76 = iadd v10, v10
    v79 = iadd v76, v10
    v93 = iadd v79, v10
    v130 = iadd v10, v93
    v176 = iadd v10, v130
    v177 = rotl v0, v176
    v45 = bitrev v177
    v679 = iconst.i32 10
    v681 = rotl v45, v679  ; v679 = 10
    v59 = bitrev v681
    v376 = iconst.i32 0xffff_fffd
    v1116 = uextend.i32 v1
    v1161 = isub v376, v1116  ; v376 = 0xffff_fffd
    v1936 = rotl v59, v1161
    return v1936
}

</details>

~This testcase spends a huge amount of time in egraphs with this PR and it now fails where it didn't before. Although I'm not 100% sure this isn't a bug in one of the rules that wasn't discovered previously.~

~I'm going to look into this again later today~

Edit: This ended up being a RISC-V bug (#7491), but I think it's still worth looking at the testcase, we now spend a bunch of time building values which I'm not sure is intended.

view this post on Zulip Wasmtime GitHub notifications bot (Nov 07 2023 at 17:17):

fitzgen commented on issue #7465:

Thanks for digging into that @afonso360!

Last updated: Nov 22 2024 at 16:03 UTC