Add a per target max vector alignment field (e.g., 32-byte alignment for x86 due to
AVX). Currently, if no aligned attribute is specified the alignment of a vector is
inferred from its size. Thus, very large vectors will be over-aligned with no
benefit. Target owners should set this target max.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@160209 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/clang/Basic/TargetInfo.h b/include/clang/Basic/TargetInfo.h
index 125496a..54d49e6 100644
--- a/include/clang/Basic/TargetInfo.h
+++ b/include/clang/Basic/TargetInfo.h
@@ -80,6 +80,7 @@
unsigned char LongLongWidth, LongLongAlign;
unsigned char SuitableAlign;
unsigned char MaxAtomicPromoteWidth, MaxAtomicInlineWidth;
+ unsigned short MaxVectorAlign;
const char *DescriptionString;
const char *UserLabelPrefix;
const char *MCountName;
@@ -308,6 +309,9 @@
/// inlined given the supported features of the given target.
unsigned getMaxAtomicInlineWidth() const { return MaxAtomicInlineWidth; }
+ /// \brief Return the maximum vector alignment supported for the given target.
+ unsigned getMaxVectorAlign() const { return MaxVectorAlign; }
+
/// \brief Return the size of intmax_t and uintmax_t for this target, in bits.
unsigned getIntMaxTWidth() const {
return getTypeWidth(IntMaxType);
diff --git a/lib/AST/ASTContext.cpp b/lib/AST/ASTContext.cpp
index a9681d8..b0351d6 100644
--- a/lib/AST/ASTContext.cpp
+++ b/lib/AST/ASTContext.cpp
@@ -1047,6 +1047,10 @@
Align = llvm::NextPowerOf2(Align);
Width = llvm::RoundUpToAlignment(Width, Align);
}
+ // Adjust the alignment based on the target max.
+ uint64_t TargetVectorAlign = Target->getMaxVectorAlign();
+ if (TargetVectorAlign && TargetVectorAlign < Align)
+ Align = TargetVectorAlign;
break;
}
diff --git a/lib/Basic/TargetInfo.cpp b/lib/Basic/TargetInfo.cpp
index 8c49486..db5941a 100644
--- a/lib/Basic/TargetInfo.cpp
+++ b/lib/Basic/TargetInfo.cpp
@@ -47,6 +47,7 @@
LargeArrayMinWidth = 0;
LargeArrayAlign = 0;
MaxAtomicPromoteWidth = MaxAtomicInlineWidth = 0;
+ MaxVectorAlign = 0;
SizeType = UnsignedLong;
PtrDiffType = SignedLong;
IntMaxType = SignedLongLong;
diff --git a/lib/Basic/Targets.cpp b/lib/Basic/Targets.cpp
index 3df59c3..1932413 100644
--- a/lib/Basic/Targets.cpp
+++ b/lib/Basic/Targets.cpp
@@ -2448,6 +2448,7 @@
LongDoubleWidth = 128;
LongDoubleAlign = 128;
SuitableAlign = 128;
+ MaxVectorAlign = 256;
SizeType = UnsignedLong;
IntPtrType = SignedLong;
DescriptionString = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-"
@@ -2755,6 +2756,7 @@
DarwinX86_64TargetInfo(const std::string& triple)
: DarwinTargetInfo<X86_64TargetInfo>(triple) {
Int64Type = SignedLongLong;
+ MaxVectorAlign = 256;
}
};
} // end anonymous namespace
diff --git a/test/CodeGen/vector-alignment.c b/test/CodeGen/vector-alignment.c
new file mode 100644
index 0000000..92d1ae7
--- /dev/null
+++ b/test/CodeGen/vector-alignment.c
@@ -0,0 +1,38 @@
+// RUN: %clang_cc1 -w -triple x86_64-apple-darwin10 -emit-llvm -o - %s | FileCheck %s
+// rdar://11759609
+
+// At or below target max alignment with no aligned attribute should align based
+// on the size of vector.
+double __attribute__((vector_size(16))) v1;
+// CHECK: @v1 {{.*}}, align 16
+double __attribute__((vector_size(32))) v2;
+// CHECK: @v2 {{.*}}, align 32
+
+// Alignment above target max alignment with no aligned attribute should align
+// based on the target max.
+double __attribute__((vector_size(64))) v3;
+// CHECK: @v3 {{.*}}, align 32
+double __attribute__((vector_size(1024))) v4;
+// CHECK: @v4 {{.*}}, align 32
+
+// Aliged attribute should always override.
+double __attribute__((vector_size(16), aligned(16))) v5;
+// CHECK: @v5 {{.*}}, align 16
+double __attribute__((vector_size(16), aligned(64))) v6;
+// CHECK: @v6 {{.*}}, align 64
+double __attribute__((vector_size(32), aligned(16))) v7;
+// CHECK: @v7 {{.*}}, align 16
+double __attribute__((vector_size(32), aligned(64))) v8;
+// CHECK: @v8 {{.*}}, align 64
+
+// Check non-power of 2 widths.
+double __attribute__((vector_size(24))) v9;
+// CHECK: @v9 {{.*}}, align 32
+double __attribute__((vector_size(40))) v10;
+// CHECK: @v10 {{.*}}, align 32
+
+// Check non-power of 2 widths with aligned attribute.
+double __attribute__((vector_size(24), aligned(64))) v11;
+// CHECK: @v11 {{.*}}, align 64
+double __attribute__((vector_size(80), aligned(16))) v12;
+// CHECK: @v12 {{.*}}, align 16