Auto merge of #123645 - matthiaskrgr:rollup-yd8d7f1, r=matthiaskrgr

Rollup of 9 pull requests

Successful merges:

 - #122781 (Fix argument ABI for overaligned structs on ppc64le)
 - #123367 (Safe Transmute: Compute transmutability from `rustc_target::abi::Layout`)
 - #123518 (Fix `ByMove` coroutine-closure shim (for 2021 precise closure capturing behavior))
 - #123547 (bootstrap: remove unused pub fns)
 - #123564 (Don't emit divide-by-zero panic paths in `StepBy::len`)
 - #123578 (Restore `pred_known_to_hold_modulo_regions`)
 - #123591 (Remove unnecessary cast from `LLVMRustGetInstrProfIncrementIntrinsic`)
 - #123632 (parser: reduce visibility of unnecessary public `UnmatchedDelim`)
 - #123635 (CFI: Fix ICE in KCFI non-associated function pointers)

r? `@ghost`
`@rustbot` modify labels: rollup

1 files changed, 4 insertions, 1 deletions

diff --git a/compiler/rustc_codegen_llvm/src/abi.rs b/compiler/rustc_codegen_llvm/src/abi.rs
index d2828669d43..f918facc86d 100644
--- a/compiler/rustc_codegen_llvm/src/abi.rs
+++ b/compiler/rustc_codegen_llvm/src/abi.rs
@@ -150,7 +150,10 @@ impl LlvmType for CastTarget {
         // Simplify to a single unit or an array if there's no prefix.
         // This produces the same layout, but using a simpler type.
         if self.prefix.iter().all(|x| x.is_none()) {
-            if rest_count == 1 {
+            // We can't do this if is_consecutive is set and the unit would get
+            // split on the target. Currently, this is only relevant for i128
+            // registers.
+            if rest_count == 1 && (!self.rest.is_consecutive || self.rest.unit != Reg::i128()) {
                 return rest_ll_unit;
             }