1; RUN: llc < %s -mtriple=x86_64-unknown-linux -O2 | FileCheck %s 2 3; This test checks that: 4; (1) mempcpy is lowered as memcpy, and 5; (2) its return value is DST+N i.e. the dst pointer adjusted by the copy size. 6; To keep the testing of (2) independent of the exact instructions used to 7; adjust the dst pointer, DST+N is explicitly computed and stored to a global 8; variable G before the mempcpy call. This instance of DST+N causes the repeat 9; DST+N done in the context of the return value of mempcpy to be redundant, and 10; the first instance to be reused as the return value. This allows the check for 11; (2) to be expressed as verifying that the MOV to store DST+N to G and 12; the MOV to copy DST+N to %rax use the same source register. 13 14; Also see mempcpy-32.ll 15 16@G = common dso_local global ptr null, align 8 17 18; CHECK-LABEL: RET_MEMPCPY: 19; CHECK: movq [[REG:%r[a-z0-9]+]], {{.*}}G 20; CHECK: callq {{.*}}memcpy 21; CHECK: movq [[REG]], %rax 22; 23define dso_local ptr @RET_MEMPCPY(ptr %DST, ptr %SRC, i64 %N) { 24 %add.ptr = getelementptr inbounds i8, ptr %DST, i64 %N 25 store ptr %add.ptr, ptr @G, align 8 26 %call = tail call ptr @mempcpy(ptr %DST, ptr %SRC, i64 %N) 27 ret ptr %call 28} 29 30declare ptr @mempcpy(ptr, ptr, i64) 31