PNaCl: Fix negative relocation addends on x86-32

test/NaCl/ARM/negative-addend.ll

Index: test/NaCl/ARM/negative-addend.ll
diff --git a/test/NaCl/ARM/negative-addend.ll b/test/NaCl/ARM/negative-addend.ll
new file mode 100644
index 0000000000000000000000000000000000000000..41d7eba43c133b388dd8db54b9f238675e8b0f1e
--- /dev/null
+++ b/test/NaCl/ARM/negative-addend.ll
@@ -0,0 +1,19 @@
+; RUN: pnacl-llc -mtriple=arm-unknown-nacl -filetype=obj %s -o - \
+; RUN:   | llvm-objdump -r - | FileCheck %s -check-prefix=ARM
+
+; Check that "add" works for negative values when used as a
+; ConstantExpr in a global variable initializer.
+; See: https://code.google.com/p/nativeclient/issues/detail?id=3548
+
+
+; @spacer and @var end up in the BSS section.
+; @spacer is at offset 0.  @var is at offset 4096 = 0x1000.
+
+@spacer = internal global [4096 x i8] zeroinitializer
+@var = internal global i32 zeroinitializer
+
+@negative_offset = internal global i32 add
+    (i32 ptrtoint (i32* @var to i32), i32 -8)
+
+; ARM: RELOCATION RECORDS FOR [.data.rel.local]:
+; ARM-NEXT: 0 R_ARM_ABS32 .bss