xref: /llvm-project/llvm/test/CodeGen/AArch64/soft-float-abi.ll (revision ef395a492aa931f428e99e1c0a93d4ad2fb0fcfa)
1; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py UTC_ARGS: --version 4
2; RUN: llc --mtriple aarch64-none-eabi < %s -mattr=-fp-armv8 | FileCheck %s
3
4; See also clang/test/CodeGen/aarch64-soft-float-abi.c, which tests the clang
5; parts of the soft-float ABI.
6
7; FP types up to 64-bit are passed in a general purpose register.
8define half @test0(half %a, half %b)  {
9; CHECK-LABEL: test0:
10; CHECK:       // %bb.0: // %entry
11; CHECK-NEXT:    mov w0, w1
12; CHECK-NEXT:    ret
13entry:
14  ret half %b
15}
16
17define bfloat @test1(i32 %a, bfloat %b) {
18; CHECK-LABEL: test1:
19; CHECK:       // %bb.0: // %entry
20; CHECK-NEXT:    mov w0, w1
21; CHECK-NEXT:    ret
22entry:
23  ret bfloat %b
24}
25
26define float @test2(i64 %a, float %b) {
27; CHECK-LABEL: test2:
28; CHECK:       // %bb.0: // %entry
29; CHECK-NEXT:    mov w0, w1
30; CHECK-NEXT:    ret
31entry:
32  ret float %b
33}
34
35define double @test3(half %a, double %b) {
36; CHECK-LABEL: test3:
37; CHECK:       // %bb.0: // %entry
38; CHECK-NEXT:    mov x0, x1
39; CHECK-NEXT:    ret
40entry:
41  ret double %b
42}
43
44; fp128 is passed in a pair of GPRs.
45define fp128 @test4(fp128 %a, fp128 %b) {
46; CHECK-LABEL: test4:
47; CHECK:       // %bb.0: // %entry
48; CHECK-NEXT:    mov x1, x3
49; CHECK-NEXT:    mov x0, x2
50; CHECK-NEXT:    ret
51entry:
52  ret fp128 %b
53}
54
55; fp128 is passed in an aligned pair of GPRs, leaving one register unused is
56; necessary.
57define fp128 @test5(float %a, fp128 %b) {
58; CHECK-LABEL: test5:
59; CHECK:       // %bb.0: // %entry
60; CHECK-NEXT:    mov x1, x3
61; CHECK-NEXT:    mov x0, x2
62; CHECK-NEXT:    ret
63entry:
64  ret fp128 %b
65}
66
67; If the alignment of an fp128 leaves a register unused, it remains unused even
68; if a later argument could fit in it.
69define i64 @test6(i64 %a, fp128 %b, i64 %c) {
70; CHECK-LABEL: test6:
71; CHECK:       // %bb.0: // %entry
72; CHECK-NEXT:    mov x0, x4
73; CHECK-NEXT:    ret
74entry:
75  ret i64 %c
76}
77
78; HFAs are all bit-casted to integer types in the frontend when using the
79; soft-float ABI, so they get passed in the same way as non-homeogeneous
80; aggregates. The IR is identical to the equivalent integer types, so nothing
81; to test here.
82
83; The PCS for vector and HVA types is not defined by the soft-float ABI because
84; these types are only defined by the ACLE when vector hardware is available,
85; so nothing to test here.
86
87; The front-end generates IR for va_arg which always reads from the integer
88; register save area, and never the floating-point register save area. The
89; layout of the va_list type remains the same, the floating-point related
90; fields are unused. The only change needed in the backend is  in va_start, to
91; not attempt to save the floating-point registers or set the FP fields in the
92; va_list.
93%struct.__va_list = type { ptr, ptr, ptr, i32, i32 }
94declare void @llvm.va_start(ptr)
95define double @test20(i32 %a, ...) {
96; CHECK-LABEL: test20:
97; CHECK:       // %bb.0: // %entry
98; CHECK-NEXT:    sub sp, sp, #96
99; CHECK-NEXT:    .cfi_def_cfa_offset 96
100; CHECK-NEXT:    mov w8, #-56 // =0xffffffc8
101; CHECK-NEXT:    add x10, sp, #8
102; CHECK-NEXT:    add x9, sp, #96
103; CHECK-NEXT:    str x8, [sp, #88]
104; CHECK-NEXT:    add x10, x10, #56
105; CHECK-NEXT:    ldrsw x8, [sp, #88]
106; CHECK-NEXT:    stp x1, x2, [sp, #8]
107; CHECK-NEXT:    stp x3, x4, [sp, #24]
108; CHECK-NEXT:    stp x5, x6, [sp, #40]
109; CHECK-NEXT:    stp x7, x9, [sp, #56]
110; CHECK-NEXT:    str x10, [sp, #72]
111; CHECK-NEXT:    tbz w8, #31, .LBB7_3
112; CHECK-NEXT:  // %bb.1: // %vaarg.maybe_reg
113; CHECK-NEXT:    add w9, w8, #8
114; CHECK-NEXT:    cmn w8, #8
115; CHECK-NEXT:    str w9, [sp, #88]
116; CHECK-NEXT:    b.gt .LBB7_3
117; CHECK-NEXT:  // %bb.2: // %vaarg.in_reg
118; CHECK-NEXT:    ldr x9, [sp, #72]
119; CHECK-NEXT:    add x8, x9, x8
120; CHECK-NEXT:    b .LBB7_4
121; CHECK-NEXT:  .LBB7_3: // %vaarg.on_stack
122; CHECK-NEXT:    ldr x8, [sp, #64]
123; CHECK-NEXT:    add x9, x8, #8
124; CHECK-NEXT:    str x9, [sp, #64]
125; CHECK-NEXT:  .LBB7_4: // %vaarg.end
126; CHECK-NEXT:    ldr x0, [x8]
127; CHECK-NEXT:    add sp, sp, #96
128; CHECK-NEXT:    ret
129entry:
130  %vl = alloca %struct.__va_list, align 8
131  call void @llvm.va_start(ptr nonnull %vl)
132  %gr_offs_p = getelementptr inbounds %struct.__va_list, ptr %vl, i64 0, i32 3
133  %gr_offs = load i32, ptr %gr_offs_p, align 8
134  %0 = icmp sgt i32 %gr_offs, -1
135  br i1 %0, label %vaarg.on_stack, label %vaarg.maybe_reg
136
137vaarg.maybe_reg:                                  ; preds = %entry
138  %new_reg_offs = add nsw i32 %gr_offs, 8
139  store i32 %new_reg_offs, ptr %gr_offs_p, align 8
140  %inreg = icmp slt i32 %gr_offs, -7
141  br i1 %inreg, label %vaarg.in_reg, label %vaarg.on_stack
142
143vaarg.in_reg:                                     ; preds = %vaarg.maybe_reg
144  %reg_top_p = getelementptr inbounds %struct.__va_list, ptr %vl, i64 0, i32 1
145  %reg_top = load ptr, ptr %reg_top_p, align 8
146  %1 = sext i32 %gr_offs to i64
147  %2 = getelementptr inbounds i8, ptr %reg_top, i64 %1
148  br label %vaarg.end
149
150vaarg.on_stack:                                   ; preds = %vaarg.maybe_reg, %entry
151  %stack = load ptr, ptr %vl, align 8
152  %new_stack = getelementptr inbounds i8, ptr %stack, i64 8
153  store ptr %new_stack, ptr %vl, align 8
154  br label %vaarg.end
155
156vaarg.end:                                        ; preds = %vaarg.on_stack, %vaarg.in_reg
157  %vaargs.addr = phi ptr [ %2, %vaarg.in_reg ], [ %stack, %vaarg.on_stack ]
158  %3 = load double, ptr %vaargs.addr, align 8
159  ret double %3
160}
161
162