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| author | Lang Hames <lhames@gmail.com> | 2011-10-10 23:42:08 +0000 |
|---|---|---|
| committer | Lang Hames <lhames@gmail.com> | 2011-10-10 23:42:08 +0000 |
| commit | bb5b3f33594cfa40e9f53bf9a71af359b080a697 (patch) | |
| tree | 6b21d9566d315610c50baf3e3492c84d1de5b16f /lib/Target/X86/README.txt | |
| parent | 15565ad758ae28f21a1f8bbcc92fac49482bd820 (diff) | |
| download | llvm-bb5b3f33594cfa40e9f53bf9a71af359b080a697.tar.gz llvm-bb5b3f33594cfa40e9f53bf9a71af359b080a697.tar.bz2 llvm-bb5b3f33594cfa40e9f53bf9a71af359b080a697.tar.xz | |
Add a natural stack alignment field to TargetData, and prevent InstCombine from
promoting allocas to preferred alignments that exceed the natural
alignment. This avoids some potentially expensive dynamic stack realignments.
The natural stack alignment is set in target data strings via the "S<size>"
option. Size is in bits and must be a multiple of 8. The natural stack alignment
defaults to "unspecified" (represented by a zero value), and the "unspecified"
value does not prevent any alignment promotions. Target maintainers that care
about avoiding promotions should explicitly add the "S<size>" option to their
target data strings.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@141599 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/Target/X86/README.txt')
| -rw-r--r-- | lib/Target/X86/README.txt | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/lib/Target/X86/README.txt b/lib/Target/X86/README.txt index b98f5fbb99..b407955060 100644 --- a/lib/Target/X86/README.txt +++ b/lib/Target/X86/README.txt @@ -1217,7 +1217,7 @@ Also check why xmm7 is not used at all in the function. Take the following: -target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:128:128" +target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:128:128-S128" target triple = "i386-apple-darwin8" @in_exit.4870.b = internal global i1 false ; <i1*> [#uses=2] define fastcc void @abort_gzip() noreturn nounwind { |