From 2ad5ee9e84b9fb2c7df76309c59e23f938632ae9 Mon Sep 17 00:00:00 2001 From: Ian Lynagh Date: Wed, 11 Mar 2009 16:06:15 +0000 Subject: [PATCH] Allocate the right number of words in new*PinnedByteArrayzh_fast --- rts/PrimOps.cmm | 53 +++++++++++++++++++++++++++++++---------------------- 1 file changed, 31 insertions(+), 22 deletions(-) diff --git a/rts/PrimOps.cmm b/rts/PrimOps.cmm index 272c705..adb2a64 100644 --- a/rts/PrimOps.cmm +++ b/rts/PrimOps.cmm @@ -88,18 +88,26 @@ newByteArrayzh_fast newPinnedByteArrayzh_fast { - W_ words, payload_words, n, p; + W_ words, bytes, payload_words, p; MAYBE_GC(NO_PTRS,newPinnedByteArrayzh_fast); - n = R1; - payload_words = ROUNDUP_BYTES_TO_WDS(n); - - words = payload_words + ((SIZEOF_StgArrWords + BA_MASK) & ~BA_MASK); + bytes = R1; + /* payload_words is what we will tell the profiler we had to allocate */ + payload_words = ROUNDUP_BYTES_TO_WDS(bytes); + /* When we actually allocate memory, we need to allow space for the + header: */ + bytes = bytes + SIZEOF_StgArrWords; + /* And we want to align to BA_ALIGN bytes, so we need to allow space + to shift up to BA_ALIGN - 1 bytes: */ + bytes = bytes + BA_ALIGN - 1; + /* Now we convert to a number of words: */ + words = ROUNDUP_BYTES_TO_WDS(bytes); ("ptr" p) = foreign "C" allocatePinned(words) []; TICK_ALLOC_PRIM(SIZEOF_StgArrWords,WDS(payload_words),0); - // This bumps p forwards so that the payload falls on an R2-byte boundary. + /* Now we need to move p forward so that the payload is aligned + to BA_ALIGN bytes: */ p = p + ((-p - SIZEOF_StgArrWords) & BA_MASK); SET_HDR(p, stg_ARR_WORDS_info, W_[CCCS]); @@ -109,30 +117,31 @@ newPinnedByteArrayzh_fast newAlignedPinnedByteArrayzh_fast { - W_ words, payload_words, n, p, mask; + W_ words, bytes, payload_words, p, alignment; MAYBE_GC(NO_PTRS,newAlignedPinnedByteArrayzh_fast); - n = R1; + bytes = R1; + alignment = R2; - if (R2 > SIZEOF_W) { - mask = R2 - 1; - } else { - mask = 0; - } - - payload_words = ROUNDUP_BYTES_TO_WDS(n); + /* payload_words is what we will tell the profiler we had to allocate */ + payload_words = ROUNDUP_BYTES_TO_WDS(bytes); - // We want an -byte aligned array. allocatePinned() gives us - // 8-byte aligned memory by default, but we want to align the - // *goods* inside the ArrWords object, so we have to check the - // size of the ArrWords header and adjust our size accordingly. - words = payload_words + ((SIZEOF_StgArrWords + mask) & ~mask); + /* When we actually allocate memory, we need to allow space for the + header: */ + bytes = bytes + SIZEOF_StgArrWords; + /* And we want to align to bytes, so we need to allow space + to shift up to bytes: */ + bytes = bytes + alignment - 1; + /* Now we convert to a number of words: */ + words = ROUNDUP_BYTES_TO_WDS(bytes); ("ptr" p) = foreign "C" allocatePinned(words) []; TICK_ALLOC_PRIM(SIZEOF_StgArrWords,WDS(payload_words),0); - // This bumps p forwards so that the payload falls on an R2-byte boundary. - p = p + ((-p - SIZEOF_StgArrWords) & mask); + /* Now we need to move p forward so that the payload is aligned + to bytes. Note that we are assuming that + is a power of 2, which is technically not guaranteed */ + p = p + ((-p - SIZEOF_StgArrWords) & (alignment - 1)); SET_HDR(p, stg_ARR_WORDS_info, W_[CCCS]); StgArrWords_words(p) = payload_words; -- 1.7.10.4