+; RUN: llc < %s -mtriple=x86_64-linux-generic -verify-machineinstrs -mattr=sse2 | FileCheck %s
+
+; Note: This test is testing that the lowering for atomics matches what we
+; currently emit for non-atomics + the atomic restriction. The presence of
+; particular lowering detail in these tests should not be read as requiring
+; that detail for correctness unless it's related to the atomicity itself.
+; (Specifically, there were reviewer questions about the lowering for halfs
+; and their calling convention which remain unresolved.)
+
+define void @store_half(half* %fptr, half %v) {
+; CHECK-LABEL: @store_half
+; CHECK: movq %rdi, %rbx
+; CHECK: callq __gnu_f2h_ieee
+; CHECK: movw %ax, (%rbx)
+ store atomic half %v, half* %fptr unordered, align 2
+ ret void
+}
+
+define void @store_float(float* %fptr, float %v) {
+; CHECK-LABEL: @store_float
+; CHECK: movd %xmm0, %eax
+; CHECK: movl %eax, (%rdi)
+ store atomic float %v, float* %fptr unordered, align 4
+ ret void
+}
+
+define void @store_double(double* %fptr, double %v) {
+; CHECK-LABEL: @store_double
+; CHECK: movd %xmm0, %rax
+; CHECK: movq %rax, (%rdi)
+ store atomic double %v, double* %fptr unordered, align 8
+ ret void
+}
+
+define void @store_fp128(fp128* %fptr, fp128 %v) {
+; CHECK-LABEL: @store_fp128
+; CHECK: callq __sync_lock_test_and_set_16
+ store atomic fp128 %v, fp128* %fptr unordered, align 16
+ ret void
+}
+
+define half @load_half(half* %fptr) {
+; CHECK-LABEL: @load_half
+; CHECK: movw (%rdi), %ax
+; CHECK: movzwl %ax, %edi
+; CHECK: jmp __gnu_h2f_ieee
+ %v = load atomic half, half* %fptr unordered, align 2
+ ret half %v
+}
+
+define float @load_float(float* %fptr) {
+; CHECK-LABEL: @load_float
+; CHECK: movl (%rdi), %eax
+; CHECK: movd %eax, %xmm0
+ %v = load atomic float, float* %fptr unordered, align 4
+ ret float %v
+}
+
+define double @load_double(double* %fptr) {
+; CHECK-LABEL: @load_double
+; CHECK: movq (%rdi), %rax
+; CHECK: movd %rax, %xmm0
+ %v = load atomic double, double* %fptr unordered, align 8
+ ret double %v
+}
+
+define fp128 @load_fp128(fp128* %fptr) {
+; CHECK-LABEL: @load_fp128
+; CHECK: callq __sync_val_compare_and_swap_16
+ %v = load atomic fp128, fp128* %fptr unordered, align 16
+ ret fp128 %v
+}
+
+
+; sanity check the seq_cst lowering since that's the
+; interesting one from an ordering perspective on x86.
+
+define void @store_float_seq_cst(float* %fptr, float %v) {
+; CHECK-LABEL: @store_float_seq_cst
+; CHECK: movd %xmm0, %eax
+; CHECK: xchgl %eax, (%rdi)
+ store atomic float %v, float* %fptr seq_cst, align 4
+ ret void
+}
+
+define void @store_double_seq_cst(double* %fptr, double %v) {
+; CHECK-LABEL: @store_double_seq_cst
+; CHECK: movd %xmm0, %rax
+; CHECK: xchgq %rax, (%rdi)
+ store atomic double %v, double* %fptr seq_cst, align 8
+ ret void
+}
+
+define float @load_float_seq_cst(float* %fptr) {
+; CHECK-LABEL: @load_float_seq_cst
+; CHECK: movl (%rdi), %eax
+; CHECK: movd %eax, %xmm0
+ %v = load atomic float, float* %fptr seq_cst, align 4
+ ret float %v
+}
+
+define double @load_double_seq_cst(double* %fptr) {
+; CHECK-LABEL: @load_double_seq_cst
+; CHECK: movq (%rdi), %rax
+; CHECK: movd %rax, %xmm0
+ %v = load atomic double, double* %fptr seq_cst, align 8
+ ret double %v
+}