From a2f7b7bfa4987c102892793ab7c7483fcb8050a0 Mon Sep 17 00:00:00 2001
From: ijl <ijl@mailbox.org>
Date: Wed, 14 Feb 2024 02:30:10 +0000
Subject: [PATCH] impl_format_simd!() lift create from loop, rotate left

---
 .github/workflows/linux.yaml |  3 ++-
 src/serialize/writer/simd.rs | 20 +++++++++++++-------
 2 files changed, 15 insertions(+), 8 deletions(-)

diff --git a/.github/workflows/linux.yaml b/.github/workflows/linux.yaml
index b7ee3df9..4f7340a2 100644
--- a/.github/workflows/linux.yaml
+++ b/.github/workflows/linux.yaml
@@ -217,7 +217,8 @@ jobs:
           {
             arch: 's390x',
             cflags: '-O2 -flto -march=z10',
-            features: 'no-panic,unstable-simd,yyjson',
+            # no unstable-simd as rotate_elements_left() causes exit 125 in at least QEMU
+            features: 'no-panic,yyjson',
             rustflags: '-Z mir-opt-level=4 -C target-cpu=z10 -D warnings',
             target: 's390x-unknown-linux-gnu',
           },
diff --git a/src/serialize/writer/simd.rs b/src/serialize/writer/simd.rs
index 94a42ac8..82a12187 100644
--- a/src/serialize/writer/simd.rs
+++ b/src/serialize/writer/simd.rs
@@ -64,14 +64,14 @@ macro_rules! impl_format_simd {
                 }
             }
 
+            let mut v = if unlikely!(is_cross_page!(sptr)) {
+                let mut v = StrVector::default();
+                v.as_mut_array()[..nb].copy_from_slice(core::slice::from_raw_parts(sptr, nb));
+                v
+            } else {
+                StrVector::from_slice(core::slice::from_raw_parts(sptr, STRIDE))
+            };
             while nb > 0 {
-                let v = if unlikely!(is_cross_page!(sptr)) {
-                    let mut v = StrVector::default();
-                    v.as_mut_array()[..nb].copy_from_slice(core::slice::from_raw_parts(sptr, nb));
-                    v
-                } else {
-                    StrVector::from_slice(core::slice::from_raw_parts(sptr, STRIDE))
-                };
                 v.copy_to_slice(core::slice::from_raw_parts_mut(dptr, STRIDE));
                 let mut mask = (v.simd_eq(blash) | v.simd_eq(quote) | v.simd_lt(x20)).to_bitmask()
                     as u32
@@ -82,7 +82,13 @@ macro_rules! impl_format_simd {
                     break;
                 } else {
                     let cn = mask.trailing_zeros() as usize;
+                    let nb_start = nb;
                     impl_escape_unchecked!(sptr, dptr, nb, mask, cn);
+                    let mut consumed = nb_start - nb;
+                    while consumed != 0 {
+                        v = v.rotate_elements_left::<1>();
+                        consumed -= 1;
+                    }
                 }
             }