diff options
| author | Dmitry Vyukov <dvyukov@google.com> | 2021-04-21 08:01:30 +0200 |
|---|---|---|
| committer | Dmitry Vyukov <dvyukov@google.com> | 2021-04-21 14:05:20 +0200 |
| commit | ad3ce6afab30fb68cfcda40a1910b87279795c5a (patch) | |
| tree | 6a6febdaae83e071a85576bb6fa1fd5b8abb2936 /pkg/csource | |
| parent | 7ffd6ad61b0d0c6290f73b3652f79c63b305351e (diff) | |
pkg/compiler: optimize array[const] representation
Represent array[const[X, int8], N] as string["XX...X"].
This replaces potentially huge number of:
NONFAILING(*(uint8_t*)0x2000126c = 0);
NONFAILING(*(uint8_t*)0x2000126d = 0);
NONFAILING(*(uint8_t*)0x2000126e = 0);
with a single memcpy. In one reproducer we had 3991 such lines.
Also replace memcpy's with memset's when possible.
Update #1070
Diffstat (limited to 'pkg/csource')
| -rw-r--r-- | pkg/csource/csource.go | 9 | ||||
| -rw-r--r-- | pkg/csource/csource_test.go | 30 |
2 files changed, 13 insertions, 26 deletions
diff --git a/pkg/csource/csource.go b/pkg/csource/csource.go index 24717a31a..c30db6b9d 100644 --- a/pkg/csource/csource.go +++ b/pkg/csource/csource.go @@ -366,8 +366,13 @@ func (ctx *context) copyin(w *bytes.Buffer, csumSeq *int, copyin prog.ExecCopyin case prog.ExecArgResult: ctx.copyinVal(w, copyin.Addr, arg.Size, ctx.resultArgToStr(arg), arg.Format) case prog.ExecArgData: - fmt.Fprintf(w, "\tNONFAILING(memcpy((void*)0x%x, \"%s\", %v));\n", - copyin.Addr, toCString(arg.Data, arg.Readable), len(arg.Data)) + if bytes.Equal(arg.Data, bytes.Repeat(arg.Data[:1], len(arg.Data))) { + fmt.Fprintf(w, "\tNONFAILING(memset((void*)0x%x, %v, %v));\n", + copyin.Addr, arg.Data[0], len(arg.Data)) + } else { + fmt.Fprintf(w, "\tNONFAILING(memcpy((void*)0x%x, \"%s\", %v));\n", + copyin.Addr, toCString(arg.Data, arg.Readable), len(arg.Data)) + } case prog.ExecArgCsum: switch arg.Kind { case prog.ExecArgCsumInet: diff --git a/pkg/csource/csource_test.go b/pkg/csource/csource_test.go index 752ff919b..e2035b286 100644 --- a/pkg/csource/csource_test.go +++ b/pkg/csource/csource_test.go @@ -160,37 +160,19 @@ csource2(&AUTO="12345678") csource3(&AUTO) csource4(&AUTO) csource5(&AUTO) +csource6(&AUTO) `, output: ` NONFAILING(memcpy((void*)0x20000040, "\x12\x34\x56\x78", 4)); syscall(SYS_csource2, 0x20000040ul); -NONFAILING(*(uint8*)0x20000080 = 0); -NONFAILING(*(uint8*)0x20000081 = 0); -NONFAILING(*(uint8*)0x20000082 = 0); -NONFAILING(*(uint8*)0x20000083 = 0); -NONFAILING(*(uint8*)0x20000084 = 0); -NONFAILING(*(uint8*)0x20000085 = 0); -NONFAILING(*(uint8*)0x20000086 = 0); -NONFAILING(*(uint8*)0x20000087 = 0); -NONFAILING(*(uint8*)0x20000088 = 0); -NONFAILING(*(uint8*)0x20000089 = 0); +NONFAILING(memset((void*)0x20000080, 0, 10)); syscall(SYS_csource3, 0x20000080ul); -NONFAILING(*(uint8*)0x200000c0 = 0xab); -NONFAILING(*(uint8*)0x200000c1 = 0xab); -NONFAILING(*(uint8*)0x200000c2 = 0xab); -NONFAILING(*(uint8*)0x200000c3 = 0xab); -NONFAILING(*(uint8*)0x200000c4 = 0xab); -NONFAILING(*(uint8*)0x200000c5 = 0xab); -NONFAILING(*(uint8*)0x200000c6 = 0xab); -NONFAILING(*(uint8*)0x200000c7 = 0xab); -NONFAILING(*(uint8*)0x200000c8 = 0xab); -NONFAILING(*(uint8*)0x200000c9 = 0xab); +NONFAILING(memset((void*)0x200000c0, 48, 10)); syscall(SYS_csource4, 0x200000c0ul); -NONFAILING(*(uint32*)0x20000100 = 0x12345678); -NONFAILING(*(uint32*)0x20000104 = 0x12345678); -NONFAILING(*(uint32*)0x20000108 = 0x12345678); -NONFAILING(*(uint32*)0x2000010c = 0x12345678); +NONFAILING(memcpy((void*)0x20000100, "0101010101", 10)); syscall(SYS_csource5, 0x20000100ul); +NONFAILING(memcpy((void*)0x20000140, "101010101010", 12)); +syscall(SYS_csource6, 0x20000140ul); `, }, } |