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authorLang Hames <lhames@gmail.com>2011-10-10 23:42:08 +0000
committerLang Hames <lhames@gmail.com>2011-10-10 23:42:08 +0000
commitbb5b3f33594cfa40e9f53bf9a71af359b080a697 (patch)
tree6b21d9566d315610c50baf3e3492c84d1de5b16f /lib/Target/ARM/ARMTargetMachine.cpp
parent15565ad758ae28f21a1f8bbcc92fac49482bd820 (diff)
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/ARM/ARMTargetMachine.cpp')
-rw-r--r--lib/Target/ARM/ARMTargetMachine.cpp15
1 files changed, 11 insertions, 4 deletions
diff --git a/lib/Target/ARM/ARMTargetMachine.cpp b/lib/Target/ARM/ARMTargetMachine.cpp
index f779ede3e3..96b1e89b0d 100644
--- a/lib/Target/ARM/ARMTargetMachine.cpp
+++ b/lib/Target/ARM/ARMTargetMachine.cpp
@@ -53,9 +53,12 @@ ARMTargetMachine::ARMTargetMachine(const Target &T, StringRef TT,
: ARMBaseTargetMachine(T, TT, CPU, FS, RM, CM), InstrInfo(Subtarget),
DataLayout(Subtarget.isAPCS_ABI() ?
std::string("e-p:32:32-f64:32:64-i64:32:64-"
- "v128:32:128-v64:32:64-n32") :
+ "v128:32:128-v64:32:64-n32-S32") :
+ Subtarget.isAAPCS_ABI() ?
std::string("e-p:32:32-f64:64:64-i64:64:64-"
- "v128:64:128-v64:64:64-n32")),
+ "v128:64:128-v64:64:64-n32-S64") :
+ std::string("e-p:32:32-f64:64:64-i64:64:64-"
+ "v128:64:128-v64:64:64-n32-S32")),
ELFWriterInfo(*this),
TLInfo(*this),
TSInfo(*this),
@@ -75,10 +78,14 @@ ThumbTargetMachine::ThumbTargetMachine(const Target &T, StringRef TT,
DataLayout(Subtarget.isAPCS_ABI() ?
std::string("e-p:32:32-f64:32:64-i64:32:64-"
"i16:16:32-i8:8:32-i1:8:32-"
- "v128:32:128-v64:32:64-a:0:32-n32") :
+ "v128:32:128-v64:32:64-a:0:32-n32-S32") :
+ Subtarget.isAAPCS_ABI() ?
+ std::string("e-p:32:32-f64:64:64-i64:64:64-"
+ "i16:16:32-i8:8:32-i1:8:32-"
+ "v128:64:128-v64:64:64-a:0:32-n32-S64") :
std::string("e-p:32:32-f64:64:64-i64:64:64-"
"i16:16:32-i8:8:32-i1:8:32-"
- "v128:64:128-v64:64:64-a:0:32-n32")),
+ "v128:64:128-v64:64:64-a:0:32-n32-S32")),
ELFWriterInfo(*this),
TLInfo(*this),
TSInfo(*this),