llvm/test/MC/ARM/arm_fixups.s
Kevin Enderby 1a47d66496 Change the ARM assembler to require a :lower16: or :upper16 on non-constant
expressions for mov instructions instead of silently truncating by default.

For the ARM assembler, we want to avoid misleadingly allowing something
like "mov r0, <symbol>" especially when we turn it into a movw and the
expression <symbol> does not have a :lower16: or :upper16" as part of the
expression.  We don't want the behavior of silently truncating, which can be
unexpected and lead to bugs that are difficult to find since this is an easy
mistake to make.

This does change the previous behavior of llvm but actually matches an
older gnu assembler that would not allow this but print less useful errors
of like “invalid constant (0x927c0) after fixup” and “unsupported relocation on
symbol foo”.  The error for llvm is "immediate expression for mov requires
:lower16: or :upper16" with correct location information on the operand
as shown in the added test cases.

rdar://12342160


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206669 91177308-0d34-0410-b5e6-96231b3b80d8
2014-04-18 23:06:39 +00:00

35 lines
1.8 KiB
ArmAsm

@ RUN: llvm-mc -triple armv7-unknown-unknown %s --show-encoding > %t
@ RUN: FileCheck < %t %s
@ RUN: llvm-mc -triple armebv7-unknown-unknown %s --show-encoding > %t
@ RUN: FileCheck --check-prefix=CHECK-BE < %t %s
bl _printf
@ CHECK: bl _printf @ encoding: [A,A,A,0xeb]
@ CHECK: @ fixup A - offset: 0, value: _printf, kind: fixup_arm_uncondbl
@ CHECK-BE: bl _printf @ encoding: [0xeb,A,A,A]
@ CHECK-BE: @ fixup A - offset: 0, value: _printf, kind: fixup_arm_uncondbl
mov r9, :lower16:(_foo)
movw r9, :lower16:(_foo)
movt r9, :upper16:(_foo)
@ CHECK: movw r9, :lower16:_foo @ encoding: [A,0x90'A',0b0000AAAA,0xe3]
@ CHECK: @ fixup A - offset: 0, value: _foo, kind: fixup_arm_movw_lo16
@ CHECK-BE: movw r9, :lower16:_foo @ encoding: [0xe3,0b0000AAAA,0x90'A',A]
@ CHECK-BE: @ fixup A - offset: 0, value: _foo, kind: fixup_arm_movw_lo16
@ CHECK: movw r9, :lower16:_foo @ encoding: [A,0x90'A',0b0000AAAA,0xe3]
@ CHECK: @ fixup A - offset: 0, value: _foo, kind: fixup_arm_movw_lo16
@ CHECK-BE: movw r9, :lower16:_foo @ encoding: [0xe3,0b0000AAAA,0x90'A',A]
@ CHECK-BE: @ fixup A - offset: 0, value: _foo, kind: fixup_arm_movw_lo16
@ CHECK: movt r9, :upper16:_foo @ encoding: [A,0x90'A',0b0100AAAA,0xe3]
@ CHECK: @ fixup A - offset: 0, value: _foo, kind: fixup_arm_movt_hi16
@ CHECK-BE: movt r9, :upper16:_foo @ encoding: [0xe3,0b0100AAAA,0x90'A',A]
@ CHECK-BE: @ fixup A - offset: 0, value: _foo, kind: fixup_arm_movt_hi16
mov r2, :lower16:fred
@ CHECK: movw r2, :lower16:fred @ encoding: [A,0x20'A',0b0000AAAA,0xe3]
@ CHECK: @ fixup A - offset: 0, value: fred, kind: fixup_arm_movw_lo16
@ CHECK-BE: movw r2, :lower16:fred @ encoding: [0xe3,0b0000AAAA,0x20'A',A]
@ CHECK-BE: @ fixup A - offset: 0, value: fred, kind: fixup_arm_movw_lo16