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bitfield_gen: explicit branch predications

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gcc8 might get wrong branch predications on these condition checks,
and it could break the code layout.
This commit is contained in:
Luca(Wei) Chen
2020-02-24 20:35:46 +11:00
committed by Chen, Wei (Data61, Kensington NSW)
parent 99c7ff898e
commit 047ab9271a
1 changed files with 4 additions and 4 deletions
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8
tools/bitfield_gen.py
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@@ -289,7 +289,7 @@ reader_template = \
%(type)s ret;
ret = (%(block)s.words[%(index)d] & 0x%(mask)x%(suf)s) %(r_shift_op)s %(shift)d;
/* Possibly sign extend */
if (%(sign_extend)d && (ret & (1%(suf)s << (%(extend_bit)d)))) {
if (__builtin_expect(!!(%(sign_extend)d && (ret & (1%(suf)s << (%(extend_bit)d)))), %(sign_extend)d)) {
ret |= 0x%(high_bits)x;
}
return ret;
@@ -302,7 +302,7 @@ ptr_reader_template = \
ret = (%(block)s_ptr->words[%(index)d] & 0x%(mask)x%(suf)s) """ \
"""%(r_shift_op)s %(shift)d;
/* Possibly sign extend */
if (%(sign_extend)d && (ret & (1%(suf)s << (%(extend_bit)d)))) {
if (__builtin_expect(!!(%(sign_extend)d && (ret & (1%(suf)s << (%(extend_bit)d)))), %(sign_extend)d)) {
ret |= 0x%(high_bits)x;
}
return ret;
@@ -357,7 +357,7 @@ union_reader_template = \
ret = (%(union)s.words[%(index)d] & 0x%(mask)x%(suf)s) %(r_shift_op)s %(shift)d;
/* Possibly sign extend */
if (%(sign_extend)d && (ret & (1%(suf)s << (%(extend_bit)d)))) {
if (__builtin_expect(!!(%(sign_extend)d && (ret & (1%(suf)s << (%(extend_bit)d)))), %(sign_extend)d)) {
ret |= 0x%(high_bits)x;
}
return ret;
@@ -374,7 +374,7 @@ ptr_union_reader_template = \
ret = (%(union)s_ptr->words[%(index)d] & 0x%(mask)x%(suf)s) """ \
"""%(r_shift_op)s %(shift)d;
/* Possibly sign extend */
if (%(sign_extend)d && (ret & (1%(suf)s << (%(extend_bit)d)))) {
if (__builtin_expect(!!(%(sign_extend)d && (ret & (1%(suf)s << (%(extend_bit)d)))), %(sign_extend)d)) {
ret |= 0x%(high_bits)x;
}
return ret;