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| author | Russ Cox <rsc@golang.org> | 2008-11-17 17:16:50 -0800 |
|---|---|---|
| committer | Russ Cox <rsc@golang.org> | 2008-11-17 17:16:50 -0800 |
| commit | c0d91c9a6cb755b991b960b936c7bef3df016986 (patch) | |
| tree | e38a02627e76c7997a3b436a5d1ca27950438cf0 | |
| parent | 1ed5c644e2930beea483489c67d881f817c13f1d (diff) | |
| download | golang-c0d91c9a6cb755b991b960b936c7bef3df016986.tar.gz | |
work around more commonly-unreachable 6g code sequences.
R=r
DELTA=23 (23 added, 0 deleted, 0 changed)
OCL=19405
CL=19420
| -rw-r--r-- | src/cmd/cov/main.c | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/src/cmd/cov/main.c b/src/cmd/cov/main.c index 061f30267..dbd9d0dae 100644 --- a/src/cmd/cov/main.c +++ b/src/cmd/cov/main.c @@ -160,6 +160,29 @@ missing(uvlong pc, uvlong epc) return; } + if(epc - pc == 2 || epc -pc == 3) { + // check for XORL inside shift. + // (on x86 have to implement large shift with explicit zeroing). + // f+90 0x00002c9f CMPL CX,$20 + // f+93 0x00002ca2 JCS f+97(SB) + // f+95 0x00002ca4 XORL AX,AX <<< + // f+97 0x00002ca6 SHLL CL,AX + // f+99 0x00002ca8 MOVL $1,CX + // + // f+c8 0x00002cd7 CMPL CX,$40 + // f+cb 0x00002cda JCS f+d0(SB) + // f+cd 0x00002cdc XORQ AX,AX <<< + // f+d0 0x00002cdf SHLQ CL,AX + // f+d3 0x00002ce2 MOVQ $1,CX + buf[0] = 0; + machdata->das(text, pc, 0, buf, sizeof buf); + if(strncmp(buf, "XOR", 3) == 0) { + machdata->das(text, epc, 0, buf, sizeof buf); + if(strncmp(buf, "SHL", 3) == 0 || strncmp(buf, "SHR", 3) == 0) + return; + } + } + // show first instruction to make clear where we were. machdata->das(text, pc, 0, buf, sizeof buf); |