Don't fold negative offsets into cp / dp accesses to avoid relocation errors.

This can happen if the address + addend is less than the start of the cp / dp.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@143459 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Target/XCore/XCoreISelDAGToDAG.cpp b/lib/Target/XCore/XCoreISelDAGToDAG.cpp
index 4dac1cee982706b2cbc75e543273e19d014076bd..8d746ae6c37588f3fc349ca3b981b51f93b07d11 100644 (file)
--- a/lib/Target/XCore/XCoreISelDAGToDAG.cpp
+++ b/lib/Target/XCore/XCoreISelDAGToDAG.cpp
@@ -120,7 +120,7 @@ bool XCoreDAGToDAGISel::SelectADDRdpii(SDValue Addr, SDValue &Base,
     ConstantSDNode *CN = 0;
     if ((Addr.getOperand(0).getOpcode() == XCoreISD::DPRelativeWrapper)
       && (CN = dyn_cast<ConstantSDNode>(Addr.getOperand(1)))
-      && (CN->getSExtValue() % 4 == 0)) {
+      && (CN->getSExtValue() % 4 == 0 && CN->getSExtValue() >= 0)) {
       // Constant word offset from a object in the data region
       Base = Addr.getOperand(0).getOperand(0);
       Offset = CurDAG->getTargetConstant(CN->getSExtValue(), MVT::i32);
@@ -141,7 +141,7 @@ bool XCoreDAGToDAGISel::SelectADDRcpii(SDValue Addr, SDValue &Base,
     ConstantSDNode *CN = 0;
     if ((Addr.getOperand(0).getOpcode() == XCoreISD::CPRelativeWrapper)
       && (CN = dyn_cast<ConstantSDNode>(Addr.getOperand(1)))
-      && (CN->getSExtValue() % 4 == 0)) {
+      && (CN->getSExtValue() % 4 == 0 && CN->getSExtValue() >= 0)) {
       // Constant word offset from a object in the data region
       Base = Addr.getOperand(0).getOperand(0);
       Offset = CurDAG->getTargetConstant(CN->getSExtValue(), MVT::i32);

diff --git a/test/CodeGen/XCore/global_negative_offset.ll b/test/CodeGen/XCore/global_negative_offset.ll
new file mode 100644 (file)
index 0000000..0328fb0
--- /dev/null
+++ b/test/CodeGen/XCore/global_negative_offset.ll
@@ -0,0 +1,25 @@
+; RUN: llc < %s -march=xcore | FileCheck %s
+
+; Don't fold negative offsets into cp / dp accesses to avoid a relocation
+; error if the address + addend is less than the start of the cp / dp.
+
+@a = external constant [0 x i32], section ".cp.rodata"
+@b = external global [0 x i32]
+
+define i32 *@f() nounwind {
+entry:
+; CHECK: f:
+; CHECK: ldaw r11, cp[a]
+; CHECK: sub r0, r11, 4
+       %0 = getelementptr [0 x i32]* @a, i32 0, i32 -1
+       ret i32* %0
+}
+
+define i32 *@g() nounwind {
+entry:
+; CHECK: g:
+; CHECK: ldaw [[REG:r[0-9]+]], dp[b]
+; CHECK: sub r0, [[REG]], 4
+       %0 = getelementptr [0 x i32]* @b, i32 0, i32 -1
+       ret i32* %0
+}