International Business Machines Corporation

Ronald Ian McIntosh

Michael K Gschwind

William Jon Schmidt

Ulrich Weigand

Jin Song Ji

Steven Jay Munroe

Mark Peter Mendell

Roch Georges Archambault

James Lawrence McInnes

Robert F Enenkel

Allan Russell Martin

Robert William Hay

Roland Froese

Siu Chi Chan

Joanne Minish

Provided are embodiments that include a system configured to generate executable code with protection barrier instructions. The system includes a storage medium, the storage medium being coupled to a processor. The processor is configured to analyze code, mark one or more potentially unsafe instructions in the code, and identify one or more unsafe instructions from the marked one or more potentially unsafe instructions in the code. The processor is also configured to insert a protection barrier instruction into the code based at least in part on identifying the one or more unsafe instructions, and translate the code, responsive to inserting the protection barrier instruction. Also provided are embodiments for a computer-implemented method and a computer program product for generating executable code with protection barrier instructions.

Generating protection barrier instructions for executable code

Calling a function may include: determining whether a call is a direct or an indirect call. In response to determining that the call is an indirect call, a first address stored in a function pointer may be obtained, wherein the function pointer is stored at a first address in a stack frame of a calling function. Whether to execute a nested function call code sequence may be determined based on whether a tag bit in the first address stored in the function pointer is set. In response to determining that the tag bit in the first address is set, a second address stored at a nested function address location may be obtained, wherein the nested function address location is at the first address, and control may be transferred to a called function, wherein the called function is stored at the second address.

Nested function pointer calls

Corruption of call stacks is detected by using guard words placed in the call stacks. A determination is made as to whether a callee routine is to include corruption detection logic to detect corruption of stacks. Based on determining the callee routine is to include the corruption detection logic, corruption detection logic is provided in the callee routine.

Providing instructions to facilitate detection of corrupt stacks

An application that includes intrinsics defined in one architecture is to execute without change on a different architecture. Program code that depends on vector element ordering is obtained, and that program code is part of an application including one or more intrinsics. The one or more intrinsics are mapped from a first system architecture for which the application was written to a second system architecture. One or more operations of the program code are then converted from a first data layout to a second data layout. The application, including the mapped intrinsics and the converted data layout, is to be executed on a processor of the different architecture.

Layered vector architecture compatibility for cross-system portability

A method for allocating memory includes an operation that determines whether a prototype of a callee function is within a scope of a caller. The caller is a module containing a function call to the callee function. In addition, the method includes determining whether the function call includes one or more unnamed parameters when a prototype of the callee function is within the scope of the caller. Further, the method may include inserting instructions in the caller to allocate a register save area in a memory when it is determined that the function call includes one or more unnamed parameters.

Conditional stack frame allocation

Corruption of call stacks is detected by using guard words placed in the call stacks. A determination is made that a caller routine is to facilitate detection of corruption of stacks. Based on the determination, a store of a guard word in a stack frame of the caller routine is provided in the caller routine. The stored guard word is then used to detect corruption of the stack frame.

A compiler includes a vector instruction processing mechanism that generates instructions for vector instructions in a way that assures correct operation in a bi-endian environment, wherein the processor architecture contains instructions with an inherent endian bias, along with at least one memory access instruction with a contrary endian bias. The compiler uses a code generation endian preference that matches the inherent computer system endian bias. The compiler generates instructions for vector instructions by determining whether the vector instruction has an endian bias that matches the code generation endian preference. When the endian bias of the vector instruction matches the code generation endian preference, the compiler generates one or more instructions for the vector instruction as normal. When the endian bias of the vector instruction does not match the code generation endian preference, the compiler generates instructions that include one or more vector element reverse instructions to fix the mismatch.

Compiler method for generating instructions for vector operations in a multi-endian instruction set

An optimizing compiler includes a vector optimization mechanism that optimizes vector instructions by eliminating one or more vector element reverse operations. The compiler can generate code that includes multiple vector element reverse operations that are inserted by the compiler to account for a mismatch between the endian bias of the instruction and the endian preference indicated by the programmer or programming environment. The compiler then analyzes the code and reduces the number of vector element reverse operations to improve the run-time performance of the code.

Compiler optimizations for vector instructions

Corruption of call stacks is detected by using guard words placed in the call stacks. A called function executing on a processor of a computing environment checks a guard word in a stack frame of a calling function. The checking determines whether the guard word has an expected value. Based on determining the guard word has an unexpected value, an indication of corruption of the stack frame is provided.

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Ronald Ian McIntosh