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More cleanups following discussions with Alan

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Signed-off-by: Bill Schmidt <wschmidt@linux.ibm.com>
master
Bill Schmidt 5 years ago
parent 323a50cbca
commit 67e985a524
2 changed files with 43 additions and 41 deletions
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30
specification/ch_2.xml
Unescape Escape View File

@ -4080,21 +4080,21 @@ xml:id="dbdoclet.50655240_pgfId-1156194">
all be on 4-byte (integer) boundaries.</para>
</note>
</section>
<section xml:id="dbdoclet.50655240___codealign"
revisionflag="added">
<title>Code Alignment</title>
<para>
Functions must be aligned on at least a 4-byte boundary.
</para>
<para>
If a function contains any prefixed (8-byte) instructions,
functions should preferably be aligned on at least a 64-byte
boundary. In ISA 3.1, executing a prefixed instruction that
crosses a 64-byte boundary will cause a SIGILL that must be
handled by the kernel. Compilers and assemblers can avoid
this if functions are aligned on a 64-byte boundary.
</para>
</section>
</section>
<section xml:id="dbdoclet.50655240___codealign"
revisionflag="added">
<title>Code Alignment</title>
<para>
Functions must be aligned on at least a 4-byte boundary.
</para>
<para>
If a function contains any prefixed (8-byte) instructions,
functions should preferably be aligned on at least a 64-byte
boundary. In ISA 3.1, executing a prefixed instruction that
crosses a 64-byte boundary will cause a SIGILL that must be
handled by the kernel. Compilers and assemblers can avoid
this if functions are aligned on a 64-byte boundary.
</para>
</section>
</section>
<section xml:id="dbdoclet.50655240_85672">

54
specification/ch_3.xml
Unescape Escape View File

@ -2449,7 +2449,7 @@ my_func:
</entry>
<entry>
<para>Represents the <phrase revisionflag="changed">address in
the</phrase> .TOC. at which the address of
the TOC</phrase> at which the address of
the relocation entry’s symbol
<phrase revisionflag="added">plus addend</phrase>
resides during execution. This
@ -4949,7 +4949,7 @@ my_func:
</row>
<row revisionflag="added">
<entry>
<para>R_PPC64_GOT_TLSGD34</para>
<para>R_PPC64_GOT_TLSGD_PCREL34</para>
</entry>
<entry>
<para>148</para>
@ -4963,7 +4963,7 @@ my_func:
</row>
<row revisionflag="added">
<entry>
<para>R_PPC64_GOT_TLSLD34</para>
<para>R_PPC64_GOT_TLSLD_PCREL34</para>
</entry>
<entry>
<para>149</para>
@ -4977,7 +4977,7 @@ my_func:
</row>
<row revisionflag="added">
<entry>
<para>R_PPC64_GOT_TPREL34</para>
<para>R_PPC64_GOT_TPREL_PCREL34</para>
</entry>
<entry>
<para>150</para>
@ -4991,7 +4991,7 @@ my_func:
</row>
<row revisionflag="added">
<entry>
<para>R_PPC64_GOT_DTPREL34</para>
<para>R_PPC64_GOT_DTPREL_PCREL34</para>
</entry>
<entry>
<para>151</para>
@ -5328,7 +5328,7 @@ my_func:
<emphasis>r_offset</emphasis> and the instruction at
<emphasis>r_offset</emphasis> + <emphasis>r_addend</emphasis> may be
optimized by the linker; the compiler must guarantee that register
lifetimes are such that the optimization is safe. In both code
lifetimes are such that the optimization is safe. In code
sequences where this relocation is valid, the first instruction also
has another relocation at <emphasis>r_offset</emphasis>. The
R_PPC64_PCREL_OPT entry occurs immediately after that relocation in
@ -5494,13 +5494,15 @@ lxv vs1, 0(r10)</programlisting>
nop</programlisting>
<para>
However, this optimization is not universally safe, since it
changes the value of r10 following the data reference. The
compiler or programmer must ensure that the value of r10 is not
used between the two instructions nor subsequently used,
and communicate a request for this optimization
by placing an R_PPC64_PCREL_OPT relocation on the first instruction
in the sequence that provides the offset to the second instruction
in the sequence.
changes lifetimes of registers set in both instructions. In
the example, the compiler or programmer must ensure that the
value of r10 set by the first instruction is not used after
that instruction, and that vs1 is not used between the two
instructions. If these conditions are met, the linker is
informed that the optimization is safe by placing an
R_PPC64_PCREL_OPT relocation on the first instruction in the
sequence with the addend of that relocation giving the
offset to the second instruction in the sequence.
</para>
</section>
<!--
@ -5855,7 +5857,7 @@ extern void *__tls_get_addr (tls_index *ti);</programlisting>
<para>pla r3, x@got@tlsgd@pcrel</para>
</entry>
<entry>
<para>R_PPC64_GOT_TLSGD34</para>
<para>R_PPC64_GOT_TLSGD_PCREL34</para>
</entry>
<entry>
<para>x</para>
@ -6171,7 +6173,7 @@ static __thread unsigned int x3;
<para>pla r3, x1@got@tlsld@pcrel</para>
</entry>
<entry>
<para>R_PPC64_GOT_TLSLD34</para>
<para>R_PPC64_GOT_TLSLD_PCREL34</para>
</entry>
<entry>
<para>x1</para>
@ -6256,7 +6258,7 @@ static __thread unsigned int x3;
<para>pld r9, x3@got@dtprel@pcrel</para>
</entry>
<entry>
<para>R_PPC64_GOT_DTPREL34</para>
<para>R_PPC64_GOT_DTPREL_PCREL34</para>
</entry>
<entry>
<para>x3</para>
@ -6566,7 +6568,7 @@ static __thread unsigned int x3;
<para>pld r9, x3@got@dtprel@pcrel(r3)</para>
</entry>
<entry>
<para>R_PPC64_GOT_DTPREL34</para>
<para>R_PPC64_GOT_DTPREL_PCREL34</para>
</entry>
<entry>
<para>x3</para>
@ -6692,7 +6694,7 @@ static __thread unsigned int x3;
<para>pld r9, x@got@tprel@pcrel</para>
</entry>
<entry>
<para>R_PPC64_GOT_TPREL34</para>
<para>R_PPC64_GOT_TPREL_PCREL34</para>
</entry>
<entry>
<para>x</para>
@ -8376,7 +8378,7 @@ nop</programlisting>
<para>pla r3, x@got@tlsgd@pcrel</para>
</entry>
<entry>
<para>R_PPC64_GOT_TLSGD34</para>
<para>R_PPC64_GOT_TLSGD_PCREL34</para>
</entry>
<entry>
<para>x</para>
@ -8492,7 +8494,7 @@ nop</programlisting>
<para>pld r3, x@got@tprel@pcrel</para>
</entry>
<entry>
<para>R_PPC64_GOT_TPREL34</para>
<para>R_PPC64_GOT_TPREL_PCREL34</para>
</entry>
<entry>
<para>x</para>
@ -8589,7 +8591,7 @@ nop</programlisting>
<para>pla r3, x@got@tlsgd@pcrel</para>
</entry>
<entry>
<para>R_PPC64_GOT_TLSGD34</para>
<para>R_PPC64_GOT_TLSGD_PCREL34</para>
</entry>
<entry>
<para>x</para>
@ -8764,7 +8766,7 @@ nop</programlisting>
<para>pla r3, x1@got@tlsld@pcrel</para>
</entry>
<entry>
<para>R_PPC64_GOT_TLSLD34</para>
<para>R_PPC64_GOT_TLSLD_PCREL34</para>
</entry>
<entry>
<para>x1</para>
@ -8830,7 +8832,7 @@ nop</programlisting>
<para>pld r9, x3@got@dtprel@pcrel</para>
</entry>
<entry>
<para>R_PPC64_GOT_DTPREL34</para>
<para>R_PPC64_GOT_DTPREL_PCREL34</para>
</entry>
<entry>
<para>x3</para>
@ -9013,7 +9015,7 @@ nop</programlisting>
<para>pld r9, x3@got@dtprel@pcrel</para>
</entry>
<entry>
<para>R_PPC64_GOT_DTPREL34</para>
<para>R_PPC64_GOT_DTPREL_PCREL34</para>
</entry>
<entry>
<para>x3</para>
@ -9111,7 +9113,7 @@ nop</programlisting>
<para>pld r9, x@got@tprel@pcrel</para>
</entry>
<entry>
<para>R_PPC64_GOT_TPREL34</para>
<para>R_PPC64_GOT_TPREL_PCREL34</para>
</entry>
<entry>
<para>x</para>
@ -9255,7 +9257,7 @@ nop</programlisting>
<para>pld r9, x@got@tprel@pcrel</para>
</entry>
<entry>
<para>R_PPC64_GOT_TPREL34</para>
<para>R_PPC64_GOT_TPREL_PCREL34</para>
</entry>
<entry>
<para>x</para>

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