; RUN: llc -mtriple=armv7-none-eabi -mattr=+neon < %s -o - | FileCheck %s
; The following functions test the use case where an X constraint is used to
; add a dependency between an assembly instruction (vmsr in this case) and
; another instruction. In each function, we use a different type for the
; X constraint argument.
;
; We can something similar from the following C code:
; double f1(double f, int pscr_value) {
; asm volatile("vmsr fpscr,%0" : "=X" ((f)): "r" (pscr_value));
; return f+f;
; }
; CHECK-LABEL: f1
; CHECK: vmsr fpscr
; CHECK: vadd.f64
define arm_aapcs_vfpcc double @f1(double %f, i32 %pscr_value) {
entry:
%f.addr = alloca double, align 8
store double %f, ptr %f.addr, align 8
call void asm sideeffect "vmsr fpscr,$1", "=*X,r"(ptr elementtype(double) nonnull %f.addr, i32 %pscr_value) nounwind
%0 = load double, ptr %f.addr, align 8
%add = fadd double %0, %0
ret double %add
}
; int f2(int f, int pscr_value) {
; asm volatile("vmsr fpscr,%0" : "=X" ((f)): "r" (pscr_value));
; return f+f;
; }
; CHECK-LABEL: f2
; CHECK: vmsr fpscr
; CHECK: mul
define arm_aapcs_vfpcc i32 @f2(i32 %f, i32 %pscr_value) {
entry:
%f.addr = alloca i32, align 4
store i32 %f, ptr %f.addr, align 4
call void asm sideeffect "vmsr fpscr,$1", "=*X,r"(ptr elementtype(i32) nonnull %f.addr, i32 %pscr_value) nounwind
%0 = load i32, ptr %f.addr, align 4
%mul = mul i32 %0, %0
ret i32 %mul
}
; int f3(int f, int pscr_value) {
; asm volatile("vmsr fpscr,%0" : "=X" ((f)): "r" (pscr_value));
; return f+f;
; }
; typedef signed char int8_t;
; typedef __attribute__((neon_vector_type(8))) int8_t int8x8_t;
; void f3 (void)
; {
; int8x8_t vector_res_int8x8;
; unsigned int fpscr;
; asm volatile ("vmsr fpscr,%1" : "=X" ((vector_res_int8x8)) : "r" (fpscr));
; return vector_res_int8x8 * vector_res_int8x8;
; }
; CHECK-LABEL: f3
; CHECK: vmsr fpscr
; CHECK: vmul.i8
define arm_aapcs_vfpcc <8 x i8> @f3() {
entry:
%vector_res_int8x8 = alloca <8 x i8>, align 8
%0 = getelementptr inbounds <8 x i8>, ptr %vector_res_int8x8, i32 0, i32 0
call void asm sideeffect "vmsr fpscr,$1", "=*X,r"(ptr elementtype(<8 x i8>) nonnull %vector_res_int8x8, i32 undef) nounwind
%1 = load <8 x i8>, ptr %vector_res_int8x8, align 8
%mul = mul <8 x i8> %1, %1
ret <8 x i8> %mul
}
; We can emit integer constants.
; We can get this from:
; void f() {
; int x = 2;
; asm volatile ("add r0, r0, %0" : : "X" (x));
; }
;
; CHECK-LABEL: f4
; CHECK: add r0, r0, #2
define void @f4() {
entry:
tail call void asm sideeffect "add r0, r0, $0", "X"(i32 2)
ret void
}
; We can emit function labels. This is equivalent to the following C code:
; void f(void) {
; void (*x)(void) = &foo;
; asm volatile ("bl %0" : : "X" (x));
; }
; CHECK-LABEL: f5
; CHECK: bl f4
define void @f5() {
entry:
tail call void asm sideeffect "bl $0", "X"(ptr nonnull @f4)
ret void
}
declare void @foo(...)
; This tests the behavior of the X constraint when used on functions pointers,
; or functions with a cast. In the first asm call we figure out that this
; is a function pointer and emit the label. With opaque pointers, we also do
; so in the second case.
; CHECK-LABEL: f6
; CHECK: bl foo
; CHECK: bl f4
define void @f6() nounwind {
entry:
tail call void asm sideeffect "bl $0", "X"(ptr @foo) nounwind
tail call void asm sideeffect "bl $0", "X"(ptr @f4) nounwind
ret void
}
; The following IR can be generated from C code with a function like:
; void a() {
; void* a = &&A;
; asm volatile ("bl %0" : : "X" (a));
; A:
; return;
; }
;
; Ideally this would give the block address of bb, but it requires us to see
; through blockaddress, which we can't do at the moment. This might break some
; existing use cases where a user would expect to get a block label and instead
; gets the block address in a register. However, note that according to the
; "no constraints" definition this behaviour is correct (although not very nice).
; CHECK-LABEL: f7
; CHECK: bl
define void @f7() {
call void asm sideeffect "bl $0", "X"( ptr blockaddress(@f7, %bb) )
br label %bb
bb:
ret void
}
; If we use a constraint "=*X", we should get a store back to *%x (in r0).
; CHECK-LABEL: f8
; CHECK: str r{{.*}}, [r0]
define void @f8(ptr %x) {
entry:
tail call void asm sideeffect "add $0, r0, r0", "=*X"(ptr elementtype(i32) %x)
ret void
}
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