Yep. Clang says: zsh% clang -o sequencepoints sequencepoints.c sequencepoints.c:7:18: warning: multiple unsequenced modifications to 'i' [-Wunsequenced]

Yep. Clang says: zsh% clang -o sequencepoints sequencepoints.c sequencepoints.c:7:18: warning: multiple unsequenced modifications to 'i' [-Wunsequenced] int r = 1 * a[i++] + 2 * a[i++] + 3 * a[i++]; ^ ~~ 1 warning generated. And prints: zsh% ./sequencepoints 140