llvm-mirror/test/CodeGen/AArch64/inlineasm-S-constraint.ll
Peter Smith c69d5b5cbb [AArch64] Support "S" inline assembler constraint
This patch re-introduces the "S" inline assembler constraint. This matches
an absolute symbolic address or a label reference. The primary use case is

asm("adrp %0, %1\n\t"
    "add %0, %0, :lo12:%1" : "=r"(addr) : "S"(&var));

I say re-introduces as it seems like "S" was implemented in the original
AArch64 backend, but it looks like it wasn't carried forward to the merged
backend. The original implementation had A and L modifiers that could be
used to print ":lo12:" to the string. It looks like gcc doesn't use these
and :lo12: is expected to be written in the inline assembly string so I've
not implemented A and L. Clang already supports the S modifier.

Fixes PR37180

Differential Revision: https://reviews.llvm.org/D46745

llvm-svn: 332444
2018-05-16 09:33:25 +00:00

21 lines
675 B
LLVM

;RUN: llc -mtriple=aarch64-none-linux-gnu -mattr=+neon < %s | FileCheck %s
@var = global i32 0
define void @test_inline_constraint_S() {
; CHECK-LABEL: test_inline_constraint_S:
call void asm sideeffect "adrp x0, $0", "S"(i32* @var)
call void asm sideeffect "add x0, x0, :lo12:$0", "S"(i32* @var)
; CHECK: adrp x0, var
; CHECK: add x0, x0, :lo12:var
ret void
}
define i32 @test_inline_constraint_S_label(i1 %in) {
; CHECK-LABEL: test_inline_constraint_S_label:
call void asm sideeffect "adr x0, $0", "S"(i8* blockaddress(@test_inline_constraint_S_label, %loc))
; CHECK: adr x0, .Ltmp{{[0-9]+}}
br i1 %in, label %loc, label %loc2
loc:
ret i32 0
loc2:
ret i32 42
}