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cmd/asm, cmd/internal/obj/ppc64: avoid unnecessary load zeros
When instructions add, and, or, xor, and movd have constant operands in some cases more instructions are generated than necessary by the assembler. This adds more opcode/operand combinations to the optab and improves the code generation for the cases where the size and sign of the constant allows the use of 1 instructions instead of 2. Example of previous code: oris r3, r0, 0 ori r3, r3, 65533 now: ori r3, r0, 65533 This does not significantly reduce the overall binary size because the improvement depends on the constant value. Some procedures show a 1-2% reduction in size. This improvement could also be significant in cases where the extra instructions occur in a critical loop. Testcase ppc64enc.s was added to cmd/asm/internal/asm/testdata with the variations affected by this change. Updates #23845 Change-Id: I7fdf2320c95815d99f2755ba77d0c6921cd7fad7 Reviewed-on: https://go-review.googlesource.com/95135 Run-TryBot: Lynn Boger <[email protected]> TryBot-Result: Gobot Gobot <[email protected]> Reviewed-by: David Chase <[email protected]>
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| Original file line number | Diff line number | Diff line change |
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| // Copyright 2018 The Go Authors. All rights reserved. | ||
| // Use of this source code is governed by a BSD-style | ||
| // license that can be found in the LICENSE file. | ||
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| // Initial set of opcode combinations based on | ||
| // improvements to processing of constant | ||
| // operands. | ||
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| // Full set will be added at a later date. | ||
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| #include "../../../../../runtime/textflag.h" | ||
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| TEXT asmtest(SB),DUPOK|NOSPLIT,$0 | ||
| // move constants | ||
| MOVD $1, R3 // 38600001 | ||
| MOVD $-1, R4 // 3880ffff | ||
| MOVD $65535, R5 // 6005ffff | ||
| MOVD $65536, R6 // 64060001 | ||
| MOVD $-32767, R5 // 38a08001 | ||
| MOVD $-32768, R6 // 38c08000 | ||
| MOVD $1234567, R5 // 6405001260a5d687 | ||
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| // add constants | ||
| ADD $1, R3 // 38630001 | ||
| ADD $1, R3, R4 // 38830001 | ||
| ADD $-1, R4 // 3884ffff | ||
| ADD $-1, R4, R5 // 38a4ffff | ||
| ADD $65535, R5 // 601fffff7cbf2a14 | ||
| ADD $65535, R5, R6 // 601fffff7cdf2a14 | ||
| ADD $65536, R6 // 3cc60001 | ||
| ADD $65536, R6, R7 // 3ce60001 | ||
| ADD $-32767, R5 // 38a58001 | ||
| ADD $-32767, R5, R4 // 38858001 | ||
| ADD $-32768, R6 // 38c68000 | ||
| ADD $-32768, R6, R5 // 38a68000 | ||
| ADD $1234567, R5 // 641f001263ffd6877cbf2a14 | ||
| ADD $1234567, R5, R6 // 641f001263ffd6877cdf2a14 | ||
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| // and constants | ||
| ANDCC $1, R3 // 70630001 | ||
| ANDCC $1, R3, R4 // 70640001 | ||
| ANDCC $-1, R4 // 3be0ffff7fe42039 | ||
| ANDCC $-1, R4, R5 // 3be0ffff7fe52039 | ||
| ANDCC $65535, R5 // 70a5ffff | ||
| ANDCC $65535, R5, R6 // 70a6ffff | ||
| ANDCC $65536, R6 // 74c60001 | ||
| ANDCC $65536, R6, R7 // 74c70001 | ||
| ANDCC $-32767, R5 // 3be080017fe52839 | ||
| ANDCC $-32767, R5, R4 // 3be080017fe42839 | ||
| ANDCC $-32768, R6 // 3be080007fe63039 | ||
| ANDCC $-32768, R5, R6 // 3be080007fe62839 | ||
| ANDCC $1234567, R5 // 641f001263ffd6877fe52839 | ||
| ANDCC $1234567, R5, R6 // 641f001263ffd6877fe62839 | ||
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| // or constants | ||
| OR $1, R3 // 60630001 | ||
| OR $1, R3, R4 // 60640001 | ||
| OR $-1, R4 // 3be0ffff7fe42378 | ||
| OR $-1, R4, R5 // 3be0ffff7fe52378 | ||
| OR $65535, R5 // 60a5ffff | ||
| OR $65535, R5, R6 // 60a6ffff | ||
| OR $65536, R6 // 64c60001 | ||
| OR $65536, R6, R7 // 64c70001 | ||
| OR $-32767, R5 // 3be080017fe52b78 | ||
| OR $-32767, R5, R6 // 3be080017fe62b78 | ||
| OR $-32768, R6 // 3be080007fe63378 | ||
| OR $-32768, R6, R7 // 3be080007fe73378 | ||
| OR $1234567, R5 // 641f001263ffd6877fe52b78 | ||
| OR $1234567, R5, R3 // 641f001263ffd6877fe32b78 | ||
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| // or constants | ||
| XOR $1, R3 // 68630001 | ||
| XOR $1, R3, R4 // 68640001 | ||
| XOR $-1, R4 // 3be0ffff7fe42278 | ||
| XOR $-1, R4, R5 // 3be0ffff7fe52278 | ||
| XOR $65535, R5 // 68a5ffff | ||
| XOR $65535, R5, R6 // 68a6ffff | ||
| XOR $65536, R6 // 6cc60001 | ||
| XOR $65536, R6, R7 // 6cc70001 | ||
| XOR $-32767, R5 // 3be080017fe52a78 | ||
| XOR $-32767, R5, R6 // 3be080017fe62a78 | ||
| XOR $-32768, R6 // 3be080007fe63278 | ||
| XOR $-32768, R6, R7 // 3be080007fe73278 | ||
| XOR $1234567, R5 // 641f001263ffd6877fe52a78 | ||
| XOR $1234567, R5, R3 // 641f001263ffd6877fe32a78 | ||
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| RET |
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