[llvm] r239412 - The constant initialization for globals in NVPTX is generated as an
Samuel Antao
sfantao at us.ibm.com
Tue Jun 9 09:29:35 PDT 2015
Author: sfantao
Date: Tue Jun 9 11:29:34 2015
New Revision: 239412
URL: http://llvm.org/viewvc/llvm-project?rev=239412&view=rev
Log:
The constant initialization for globals in NVPTX is generated as an
array of bytes. The generation of this byte arrays was expecting
the host to be little endian, which prevents big endian hosts to be
used in the generation of the PTX code. This patch fixes the
problem by changing the way the bytes are extracted so that it
works for either little and big endian.
Added:
llvm/trunk/test/CodeGen/NVPTX/globals_init.ll
Modified:
llvm/trunk/lib/Target/NVPTX/NVPTXAsmPrinter.cpp
Modified: llvm/trunk/lib/Target/NVPTX/NVPTXAsmPrinter.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/NVPTX/NVPTXAsmPrinter.cpp?rev=239412&r1=239411&r2=239412&view=diff
==============================================================================
--- llvm/trunk/lib/Target/NVPTX/NVPTXAsmPrinter.cpp (original)
+++ llvm/trunk/lib/Target/NVPTX/NVPTXAsmPrinter.cpp Tue Jun 9 11:29:34 2015
@@ -1760,6 +1760,30 @@ void NVPTXAsmPrinter::printScalarConstan
llvm_unreachable("Not scalar type found in printScalarConstant()");
}
+// These utility functions assure we get the right sequence of bytes for a given
+// type even for big-endian machines
+template <typename T> static void ConvertIntToBytes(unsigned char *p, T val) {
+ int64_t vp = (int64_t)val;
+ for (unsigned i = 0; i < sizeof(T); ++i) {
+ p[i] = (unsigned char)vp;
+ vp >>= 8;
+ }
+}
+static void ConvertFloatToBytes(unsigned char *p, float val) {
+ int32_t *vp = (int32_t *)&val;
+ for (unsigned i = 0; i < sizeof(int32_t); ++i) {
+ p[i] = (unsigned char)*vp;
+ *vp >>= 8;
+ }
+}
+static void ConvertDoubleToBytes(unsigned char *p, double val) {
+ int64_t *vp = (int64_t *)&val;
+ for (unsigned i = 0; i < sizeof(int64_t); ++i) {
+ p[i] = (unsigned char)*vp;
+ *vp >>= 8;
+ }
+}
+
void NVPTXAsmPrinter::bufferLEByte(const Constant *CPV, int Bytes,
AggBuffer *aggBuffer) {
@@ -1773,30 +1797,30 @@ void NVPTXAsmPrinter::bufferLEByte(const
return;
}
- unsigned char *ptr;
+ unsigned char ptr[8];
switch (CPV->getType()->getTypeID()) {
case Type::IntegerTyID: {
const Type *ETy = CPV->getType();
if (ETy == Type::getInt8Ty(CPV->getContext())) {
unsigned char c = (unsigned char)cast<ConstantInt>(CPV)->getZExtValue();
- ptr = &c;
+ ConvertIntToBytes<>(ptr, c);
aggBuffer->addBytes(ptr, 1, Bytes);
} else if (ETy == Type::getInt16Ty(CPV->getContext())) {
short int16 = (short)cast<ConstantInt>(CPV)->getZExtValue();
- ptr = (unsigned char *)&int16;
+ ConvertIntToBytes<>(ptr, int16);
aggBuffer->addBytes(ptr, 2, Bytes);
} else if (ETy == Type::getInt32Ty(CPV->getContext())) {
if (const ConstantInt *constInt = dyn_cast<ConstantInt>(CPV)) {
int int32 = (int)(constInt->getZExtValue());
- ptr = (unsigned char *)&int32;
+ ConvertIntToBytes<>(ptr, int32);
aggBuffer->addBytes(ptr, 4, Bytes);
break;
} else if (const ConstantExpr *Cexpr = dyn_cast<ConstantExpr>(CPV)) {
if (const ConstantInt *constInt = dyn_cast<ConstantInt>(
ConstantFoldConstantExpression(Cexpr, *TD))) {
int int32 = (int)(constInt->getZExtValue());
- ptr = (unsigned char *)&int32;
+ ConvertIntToBytes<>(ptr, int32);
aggBuffer->addBytes(ptr, 4, Bytes);
break;
}
@@ -1811,14 +1835,14 @@ void NVPTXAsmPrinter::bufferLEByte(const
} else if (ETy == Type::getInt64Ty(CPV->getContext())) {
if (const ConstantInt *constInt = dyn_cast<ConstantInt>(CPV)) {
long long int64 = (long long)(constInt->getZExtValue());
- ptr = (unsigned char *)&int64;
+ ConvertIntToBytes<>(ptr, int64);
aggBuffer->addBytes(ptr, 8, Bytes);
break;
} else if (const ConstantExpr *Cexpr = dyn_cast<ConstantExpr>(CPV)) {
if (const ConstantInt *constInt = dyn_cast<ConstantInt>(
ConstantFoldConstantExpression(Cexpr, *TD))) {
long long int64 = (long long)(constInt->getZExtValue());
- ptr = (unsigned char *)&int64;
+ ConvertIntToBytes<>(ptr, int64);
aggBuffer->addBytes(ptr, 8, Bytes);
break;
}
@@ -1840,11 +1864,11 @@ void NVPTXAsmPrinter::bufferLEByte(const
const Type *Ty = CFP->getType();
if (Ty == Type::getFloatTy(CPV->getContext())) {
float float32 = (float) CFP->getValueAPF().convertToFloat();
- ptr = (unsigned char *)&float32;
+ ConvertFloatToBytes(ptr, float32);
aggBuffer->addBytes(ptr, 4, Bytes);
} else if (Ty == Type::getDoubleTy(CPV->getContext())) {
double float64 = CFP->getValueAPF().convertToDouble();
- ptr = (unsigned char *)&float64;
+ ConvertDoubleToBytes(ptr, float64);
aggBuffer->addBytes(ptr, 8, Bytes);
} else {
llvm_unreachable("unsupported fp const type");
Added: llvm/trunk/test/CodeGen/NVPTX/globals_init.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/NVPTX/globals_init.ll?rev=239412&view=auto
==============================================================================
--- llvm/trunk/test/CodeGen/NVPTX/globals_init.ll (added)
+++ llvm/trunk/test/CodeGen/NVPTX/globals_init.ll Tue Jun 9 11:29:34 2015
@@ -0,0 +1,23 @@
+; RUN: llc < %s -march=nvptx -mcpu=sm_20 | FileCheck %s
+
+; Make sure the globals constant initializers are not prone to host endianess
+; issues.
+
+; CHECK-DAG: .b8 Gbli08[2] = {171, 205};
+ at Gbli08 = global [2 x i8] [i8 171, i8 205]
+
+; CHECK-DAG: .b8 Gbli16[4] = {205, 171, 1, 239};
+ at Gbli16 = global [2 x i16] [i16 43981, i16 61185]
+
+; CHECK-DAG: .b8 Gbli32[8] = {1, 239, 205, 171, 137, 103, 69, 35};
+ at Gbli32 = global [2 x i32] [i32 2882400001, i32 591751049]
+
+; CHECK-DAG: .b8 Gbli64[16] = {137, 103, 69, 35, 1, 239, 205, 171, 239, 205, 171, 137, 103, 69, 35, 1};
+ at Gbli64 = global [2 x i64] [i64 12379813738877118345, i64 81985529216486895]
+
+; CHECK-DAG: .b8 Gblf32[8] = {192, 225, 100, 75, 0, 96, 106, 69};
+ at Gblf32 = global [2 x float] [float 1.5e+7, float 3.75e+3]
+
+; CHECK-DAG: .b8 Gblf64[16] = {116, 10, 181, 48, 134, 62, 230, 58, 106, 222, 138, 98, 204, 250, 200, 75};
+ at Gblf64 = global [2 x double] [double 5.75e-25, double 12.25e+56]
+
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