Arrange bread cubes on a baking sheet; bake at 425° for 5 minutes or until lightly toasted and dry. Cool completely; set aside.
Combine lemon juice and 2 1/2 tablespoons oil in a large bowl; stir with a whisk. Stir in rosemary, 1/4 teaspoon salt, pepper, and 1 garlic clove. Add tomatoes and olives; mix well.
Heat 1 1/2 teaspoons oil in a large nonstick skillet; add shrimp and 1/4 teaspoon salt. Cook 3 minutes, stirring occasionally; add 1 garlic clove. Cook 2 minutes or until shrimp are cooked through. Remove from heat.
Add bread cubes and shrimp to tomato mixture; toss. Add basil; toss to combine. Serve immediately.