Quote: it is hard for code to take a lot of time if it isn't executed a lot; typically in a loop [»bentJL_1982]

Quote: how to optimize RSA encryption and decryption; software often faster than hardware implementations [»wienMJ2_2000]

Quote: formal semantics enables compile-time optimization, analysis, and verification

Quote: when optimizing a program, measure performance before and after each change [»blocJ_2001]

Quote: optimize complex operations, then expand the operation and reoptimize; e.g., max and min, boolean expressions, and function calls [»auslM6_1982]

Quote: simplify an optimization by depending on common subexpression elimination and other standard optimizations

Quote: instead of moving code out of a loop, insert a duplicate copy; common subexpression elimination to remove the original copy [»auslM6_1982]

Quote: graph coloring allocator developed for PL.8; simplified the compiler [»auslM6_1982]

Quote: compositional verification of memory safety in optimized code; encode low-level safety information via static single-assignment (SSA) proof variables [»menoVS1_2006]

Quote: evaluate code by number of copies and memory-based arguments [»cbb_1990, OK]

Quote: algorithms should reduce memory stalls as well as instructions; sequential access is faster than random access; using registers wins on both counts [»argeL9_2000]

Quote: current compilers can generate object code within 15% of assembly code if the source exploits the strengths of the compiler's optimizer [»goodJB8_1976]

Quote: measure compiler optimizations by equivalent programs, one of which will not optimize any further [»klerM3_1988]

Quote: used Ackermann's function to compare code generators; Bliss/11 did as well as assembly code [»wichBA5_1977, OK]

Quote: compared compilers using Ackermann's function [»wichBA_1976, OK]

Quote: performance testing of cryptographic algorithms written in optimized assembly code [»prenB12_1998]

Quote: PL.8 optimizer bugs produce catastrophic results since optimizer applies to all code; regression test of 150 self-checking programs [»auslM6_1982]

Quote: with structured languages, loops in intermediate code usually via 'DO' construct

QuoteRef: zelkMV1_1974 ;;optimized a structured goto-less language and found do very little (1-3%) very much like Data General's Algol 5

Quote: for optimization, the intermediate representation should be tree-based with control flow, dominator, and use-def information included [»franM11_1998]

Quote: PL.8 used intermediate language for optimization

Quote: ESL is split into a set language and a Pascal-like base language; the compiler can optimize the set language in terms of the base language [»katzJ5_1979]

Quote: PL.8 intermediate language has string operations and symbolic registers; optimized [»auslM6_1982]

Quote: calling sequences must be compact

Quote: UNIX programs tend to use many small functions; 20% of time and space can be in function prologue, epilogue and calling sequence [»johnSC7_1978a]

Quote: final assembly generates function prologs and epilogs; handles stack frame, preserved registers [»auslM6_1982]

Quote: a calling convention is a contract between caller, callee, run-time system, and operating system; must agree on parameters, results, space allocation, reserved stack, stack inspection/modification; hard to get right [»olinR1_2006]

Quote: specify a calling convention with staged allocation; composes tiny allocators called stages; precise, formal semantics for compiler implementation and testing [»olinR1_2006]

Quote: staged allocation maps high-level types to a width, kind, and alignment, e.g., float [»olinR1_2006]

Quote: staged allocation assigns locations to a combination of registers and memory

Quote: the key instruction is the first instruction executed that causes a source-level, visible state change for an atom; compiler may annotate [»ticeC4_2001]

Quote: static single assignment (SSA) is useful for optimization

Quote: compilers can violate sequential consistency by reordering shared memory operations or allocating shared memory to registers; like relaxed consistency, it is difficult to analyze [»adveSV12_1996]

Quote: relaxed memory consistency models often provide a fence instruction or other safety net to force synchronization; these allow compilers to safely optimize large regions of code [»adveSV12_1996]

Quote: how to optimize programs for cache memory; unless hit rate 98% programs run at memory speed instead of processor speed [»searCB10_2000]

Quote: improve cache performance with locality grouping, dynamic data packing, pointer updates, and array alignment; up to 5x faster [»dingC5_1999]

Quote: to prevent memory bank thrashing, array processing programs should use sequential access to storage [»rymaJW3_1982]

Quote: improved prediction of cache behavior by analyzing calling contexts and separating first loop invocation from successive invocations [»martF3_1998]

Quote: use run-time data maps and data indirections to ensure correctness of run-time data transformations

Quote: automatically inline single-reference objects; 25% fewer cache misses; 14% faster programs [»dolbJ6_2000]

Quote: compress pointer structures by replacing pointers with computed offsets; e.g., implicit heap [»chilTM12_2000]

Quote: dead store elimination eliminates stored values that are not used [»auslM6_1982]

Quote: field analysis for inexpensive interprocedural information about a class or small set of classes [»ghemS6_2000]

Quote: field properties refine type information for reference fields; e.g., does not reference subclasses of C, contains fixed-size array [»ghemS6_2000]

Quote: ABCD-eliminate array bounds checks on demand; sparse SSA analysis; removes 45% of bounds checks [»bodiR6_2000]

Quote: trap elimination moves bounds tests from loops by modifying the loop termination test [»auslM6_1982]

Quote: PL.8 guarantees that all array and offset references are within bounds; optimizes run-time checks; checking costs 5-10% [»auslM6_1982]

Quote: to bound numeric error, a programmer must be able to predicate how the compiler generates floating-point operations [»farnC7_1988]

Quote: an optimizer should not rearrange the order of floating-point evaluation in any way that changes the computed value or side effects

Quote: AUTOCODER's macro processors generated code that was data-sensitive and context-sensitive [»halpMI1_1968]

Quote: can reduce energy consumption by assigning register labels to minimize switching costs; also compiler optimizations and better algorithms [»mehtR8_1997]

Quote: energy efficiency and price-performance are the primary factors for Google clusters

Quote: survey of power reduction techniques for circuits to architectures, system software, and applications [»venkV9_2005]

Quote: the power density and heat generation of computers is approaching that of nuclear reactors