From 4739f95b008ff61288e46a5f615e97fbdb06af01 Mon Sep 17 00:00:00 2001 From: Olivier Hainque Date: Tue, 24 Mar 2020 08:49:29 +0000 Subject: [PATCH] [Ada] Bump secondary stack alignment factor in full runtimes 2020-06-12 Olivier Hainque gcc/ada/ * libgnat/s-secsta.ads (Memory_Alignment): New constant, memory alignment for chunks and allocated blocks. Initialize to Standard'Maximum_Alignment * 2. (Chunk_Memory): Use it. * libgnat/s-secsta.adb (Round_Up): Likewise. --- gcc/ada/libgnat/s-secsta.adb | 2 +- gcc/ada/libgnat/s-secsta.ads | 19 ++++++++++++++++--- 2 files changed, 17 insertions(+), 4 deletions(-) diff --git a/gcc/ada/libgnat/s-secsta.adb b/gcc/ada/libgnat/s-secsta.adb index 0010449..7ec8462 100644 --- a/gcc/ada/libgnat/s-secsta.adb +++ b/gcc/ada/libgnat/s-secsta.adb @@ -564,7 +564,7 @@ package body System.Secondary_Stack is -------------- function Round_Up (Size : Storage_Count) return Memory_Size is - Algn_MS : constant Memory_Size := Standard'Maximum_Alignment; + Algn_MS : constant Memory_Size := Memory_Alignment; Size_MS : constant Memory_Size := Memory_Size (Size); begin diff --git a/gcc/ada/libgnat/s-secsta.ads b/gcc/ada/libgnat/s-secsta.ads index 764ae2f..d06e97f 100644 --- a/gcc/ada/libgnat/s-secsta.ads +++ b/gcc/ada/libgnat/s-secsta.ads @@ -261,10 +261,23 @@ private subtype Memory_Index is Memory_Size; -- Index into the memory storage of a single chunk + Memory_Alignment : constant := Standard'Maximum_Alignment * 2; + -- The memory alignment we will want to honor on every allocation. + -- + -- At this stage, gigi assumes we can accomodate any alignment requirement + -- there might be on the data type for which the memory gets allocated (see + -- build_call_alloc_dealloc). + -- + -- The multiplication factor is intended to account for requirements + -- by user code compiled with specific arch/cpu options such as -mavx + -- on X86[_64] targets, which Standard'Maximum_Alignment doesn't convey + -- without such compilation options. * 4 would actually be needed to + -- support -mavx512f on X86, but this would incur more annoying memory + -- consumption overheads. + type Chunk_Memory is array (Memory_Size range <>) of SSE.Storage_Element; - for Chunk_Memory'Alignment use Standard'Maximum_Alignment; - -- The memory storage of a single chunk. It utilizes maximum alignment in - -- order to guarantee efficient operations. + for Chunk_Memory'Alignment use Memory_Alignment; + -- The memory storage of a single chunk -------------- -- SS_Chunk -- -- 2.7.4