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ARM: remove ARM/Thumb distinction for preferred alignment. 

Thumb1 has legitimate reasons for preferring 32-bit alignment of types
i1/i8/i16, since the 16-bit encoding of "add rD, sp, #imm" requires #imm to be
a multiple of 4. However, this is a trade-off betweem code size and RAM usage;
the DataLayout string is not the best place to represent it even if desired.

So this patch removes the extra Thumb requirements, hopefully making ARM and
Thumb completely compatible in this respect.

llvm-svn: 219735
This commit is contained in:
Tim Northover 2014-10-14 22:12:21 +00:00
parent cf6ce0c8f7
commit 147cd2f6e5
2 changed files with 32 additions and 62 deletions
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90
clang/lib/Basic/Targets.cpp
View File

@ -3728,42 +3728,27 @@ class ARMTargetInfo : public TargetInfo {
ZeroLengthBitfieldBoundary = 0;
if (IsThumb) {
// Thumb1 add sp, #imm requires the immediate value be multiple of 4,
// so set preferred for small types to 32.
if (T.isOSBinFormatMachO()) {
DescriptionString = BigEndian ?
"E-m:o-p:32:32-i1:8:32-i8:8:32-i16:16:32-i64:64-"
"v128:64:128-a:0:32-n32-S64" :
"e-m:o-p:32:32-i1:8:32-i8:8:32-i16:16:32-i64:64-"
"v128:64:128-a:0:32-n32-S64";
} else if (T.isOSWindows()) {
// FIXME: this is invalid for WindowsCE
assert(!BigEndian && "Windows on ARM does not support big endian");
DescriptionString = "e"
"-m:e"
"-p:32:32"
"-i1:8:32-i8:8:32-i16:16:32-i64:64"
"-v128:64:128"
"-a:0:32"
"-n32"
"-S64";
} else {
DescriptionString = BigEndian ?
"E-m:e-p:32:32-i1:8:32-i8:8:32-i16:16:32-i64:64-"
"v128:64:128-a:0:32-n32-S64" :
"e-m:e-p:32:32-i1:8:32-i8:8:32-i16:16:32-i64:64-"
"v128:64:128-a:0:32-n32-S64";
}
// Thumb1 add sp, #imm requires the immediate value be multiple of 4,
// so set preferred for small types to 32.
if (T.isOSBinFormatMachO()) {
DescriptionString =
BigEndian ? "E-m:o-p:32:32-i64:64-v128:64:128-a:0:32-n32-S64"
: "e-m:o-p:32:32-i64:64-v128:64:128-a:0:32-n32-S64";
} else if (T.isOSWindows()) {
// FIXME: this is invalid for WindowsCE
assert(!BigEndian && "Windows on ARM does not support big endian");
DescriptionString = "e"
"-m:e"
"-p:32:32"
"-i64:64"
"-v128:64:128"
"-a:0:32"
"-n32"
"-S64";
} else {
if (T.isOSBinFormatMachO())
DescriptionString =
BigEndian ? "E-m:o-p:32:32-i64:64-v128:64:128-a:0:32-n32-S64"
: "e-m:o-p:32:32-i64:64-v128:64:128-a:0:32-n32-S64";
else
DescriptionString =
BigEndian ? "E-m:e-p:32:32-i64:64-v128:64:128-a:0:32-n32-S64"
: "e-m:e-p:32:32-i64:64-v128:64:128-a:0:32-n32-S64";
DescriptionString =
BigEndian ? "E-m:e-p:32:32-i64:64-v128:64:128-a:0:32-n32-S64"
: "e-m:e-p:32:32-i64:64-v128:64:128-a:0:32-n32-S64";
}
// FIXME: Enumerated types are variable width in straight AAPCS.
@ -3794,31 +3779,16 @@ class ARMTargetInfo : public TargetInfo {
/// gcc.
ZeroLengthBitfieldBoundary = 32;
if (IsThumb) {
// Thumb1 add sp, #imm requires the immediate value be multiple of 4,
// so set preferred for small types to 32.
if (T.isOSBinFormatMachO())
DescriptionString = BigEndian ?
"E-m:o-p:32:32-i1:8:32-i8:8:32-i16:16:32-f64:32:64"
"-v64:32:64-v128:32:128-a:0:32-n32-S32" :
"e-m:o-p:32:32-i1:8:32-i8:8:32-i16:16:32-f64:32:64"
"-v64:32:64-v128:32:128-a:0:32-n32-S32";
else
DescriptionString = BigEndian ?
"E-m:e-p:32:32-i1:8:32-i8:8:32-i16:16:32-f64:32:64"
"-v64:32:64-v128:32:128-a:0:32-n32-S32" :
"e-m:e-p:32:32-i1:8:32-i8:8:32-i16:16:32-f64:32:64"
"-v64:32:64-v128:32:128-a:0:32-n32-S32";
} else {
if (T.isOSBinFormatMachO())
DescriptionString = BigEndian ?
"E-m:o-p:32:32-f64:32:64-v64:32:64-v128:32:128-a:0:32-n32-S32" :
"e-m:o-p:32:32-f64:32:64-v64:32:64-v128:32:128-a:0:32-n32-S32";
else
DescriptionString = BigEndian ?
"E-m:e-p:32:32-f64:32:64-v64:32:64-v128:32:128-a:0:32-n32-S32" :
"e-m:e-p:32:32-f64:32:64-v64:32:64-v128:32:128-a:0:32-n32-S32";
}
if (T.isOSBinFormatMachO())
DescriptionString =
BigEndian
? "E-m:o-p:32:32-f64:32:64-v64:32:64-v128:32:128-a:0:32-n32-S32"
: "e-m:o-p:32:32-f64:32:64-v64:32:64-v128:32:128-a:0:32-n32-S32";
else
DescriptionString =
BigEndian
? "E-m:e-p:32:32-f64:32:64-v64:32:64-v128:32:128-a:0:32-n32-S32"
: "e-m:e-p:32:32-f64:32:64-v64:32:64-v128:32:128-a:0:32-n32-S32";
// FIXME: Override "preferred align" for double and long long.
}

4
clang/test/CodeGen/target-data.c
View File

@ -128,7 +128,7 @@
// RUN: %clang_cc1 -triple thumb-unknown-gnueabi -o - -emit-llvm %s | \
// RUN: FileCheck %s -check-prefix=THUMB
// THUMB: target datalayout = "e-m:e-p:32:32-i1:8:32-i8:8:32-i16:16:32-i64:64-v128:64:128-a:0:32-n32-S64"
// THUMB: target datalayout = "e-m:e-p:32:32-i64:64-v128:64:128-a:0:32-n32-S64"
// RUN: %clang_cc1 -triple arm-unknown-gnueabi -o - -emit-llvm %s | \
// RUN: FileCheck %s -check-prefix=ARM
@ -136,7 +136,7 @@
// RUN: %clang_cc1 -triple thumb-unknown -o - -emit-llvm -target-abi apcs-gnu \
// RUN: %s | FileCheck %s -check-prefix=THUMB-GNU
// THUMB-GNU: target datalayout = "e-m:e-p:32:32-i1:8:32-i8:8:32-i16:16:32-f64:32:64-v64:32:64-v128:32:128-a:0:32-n32-S32"
// THUMB-GNU: target datalayout = "e-m:e-p:32:32-f64:32:64-v64:32:64-v128:32:128-a:0:32-n32-S32"
// RUN: %clang_cc1 -triple arm-unknown -o - -emit-llvm -target-abi apcs-gnu \
// RUN: %s | FileCheck %s -check-prefix=ARM-GNU