assign.c
924 Bytes
// RUN: %clang_cc1 -triple x86_64 -emit-llvm -o - %s | FileCheck %s
// Check that we don't generate unnecessary reloads.
//
// CHECK-LABEL: define void @f0()
// CHECK: [[x_0:%.*]] = alloca i32, align 4
// CHECK-NEXT: [[y_0:%.*]] = alloca i32, align 4
// CHECK-NEXT: store i32 1, i32* [[x_0]]
// CHECK-NEXT: store i32 1, i32* [[x_0]]
// CHECK-NEXT: store i32 1, i32* [[y_0]]
// CHECK: }
void f0() {
int x, y;
x = 1;
y = (x = 1);
}
// This used to test that we generate reloads for volatile access,
// but that does not appear to be correct behavior for C.
//
// CHECK-LABEL: define void @f1()
// CHECK: [[x_1:%.*]] = alloca i32, align 4
// CHECK-NEXT: [[y_1:%.*]] = alloca i32, align 4
// CHECK-NEXT: store volatile i32 1, i32* [[x_1]]
// CHECK-NEXT: store volatile i32 1, i32* [[x_1]]
// CHECK-NEXT: store volatile i32 1, i32* [[y_1]]
// CHECK: }
void f1() {
volatile int x, y;
x = 1;
y = (x = 1);
}