From 79f41c773aaad6a10c2c752d223bd5aba0371f9b Mon Sep 17 00:00:00 2001 From: Jubilee Young Date: Wed, 19 Feb 2025 14:53:31 -0800 Subject: compiler: split vector_align into cabi and llvmlike Introduce a pair of functions that actually describe what they do, because it wasn't clear the alignment is sometimes a forgery. --- compiler/rustc_abi/src/callconv/reg.rs | 2 +- compiler/rustc_abi/src/lib.rs | 23 ++++++++++++++--------- 2 files changed, 15 insertions(+), 10 deletions(-) (limited to 'compiler/rustc_abi/src') diff --git a/compiler/rustc_abi/src/callconv/reg.rs b/compiler/rustc_abi/src/callconv/reg.rs index 66f47c52c15..8cf140dbaad 100644 --- a/compiler/rustc_abi/src/callconv/reg.rs +++ b/compiler/rustc_abi/src/callconv/reg.rs @@ -57,7 +57,7 @@ impl Reg { 128 => dl.f128_align.abi, _ => panic!("unsupported float: {self:?}"), }, - RegKind::Vector => dl.vector_align(self.size).abi, + RegKind::Vector => dl.llvmlike_vector_align(self.size).abi, } } } diff --git a/compiler/rustc_abi/src/lib.rs b/compiler/rustc_abi/src/lib.rs index 43a7141472c..094a25129ae 100644 --- a/compiler/rustc_abi/src/lib.rs +++ b/compiler/rustc_abi/src/lib.rs @@ -408,16 +408,21 @@ impl TargetDataLayout { } } + /// psABI-mandated alignment for a vector type, if any #[inline] - pub fn vector_align(&self, vec_size: Size) -> AbiAndPrefAlign { - for &(size, align) in &self.vector_align { - if size == vec_size { - return align; - } - } - // Default to natural alignment, which is what LLVM does. - // That is, use the size, rounded up to a power of 2. - AbiAndPrefAlign::new(Align::from_bytes(vec_size.bytes().next_power_of_two()).unwrap()) + fn cabi_vector_align(&self, vec_size: Size) -> Option { + self.vector_align + .iter() + .find(|(size, _align)| *size == vec_size) + .map(|(_size, align)| *align) + } + + /// an alignment resembling the one LLVM would pick for a vector + #[inline] + pub fn llvmlike_vector_align(&self, vec_size: Size) -> AbiAndPrefAlign { + self.cabi_vector_align(vec_size).unwrap_or(AbiAndPrefAlign::new( + Align::from_bytes(vec_size.bytes().next_power_of_two()).unwrap(), + )) } } -- cgit 1.4.1-3-g733a5