https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115138
--- Comment #21 from Iain Buclaw <ibuclaw at gcc dot gnu.org> ---
Now doing a fair comparison:
Command:
g++-11 -std=c++11 \
-fno-PIE -c -O3 -g -fno-checking -DIN_GCC -fno-exceptions \
-fno-rtti -fasynchronous-unwind-tables \
-W -Wall -Wno-narrowing -Wwrite-strings -Wcast-qual -Wno-format \
-Wmissing-format-attribute -Wconditionally-supported \
-Woverloaded-virtual -pedantic -Wno-long-long -Wno-variadic-macros \
-Wno-overlength-strings -fno-common -DHAVE_CONFIG_H -fno-PIE \
-I../stage1-gcc -I../../gcc -I../../gcc/. -I../../gcc/../include \
-I../../gcc/../libcpp/include -I../../gcc/../libcody \
-I../../gcc/../libdecnumber -I../../gcc/../libdecnumber/bid \
-I../libdecnumber -I../../gcc/../libbacktrace \
-o gimplify.o ../../gcc/gimplify.cc
Optimized-tree dump around line 6529.
```
<bb 81> [local count: 302659225]:
# _272 = PHI <is_gimple_reg_rhs_or_call(79), is_gimple_mem_rhs_or_call(80)>
# DEBUG lhs => NULL
# DEBUG final_pred => _272
# DEBUG BEGIN_STMT
if (_272 != _547)
goto <bb 83>; [53.47%]
else
goto <bb 82>; [46.53%]
<bb 82> [local count: 301785332]:
# DEBUG BEGIN_STMT
_66 = MEM[(union tree_node * *)_1 + 32B];
_67 = _66->base.code;
if (_67 == 163)
goto <bb 84>; [34.00%]
else
goto <bb 93>; [66.00%]
<bb 83> [local count: 161831887]:
# DEBUG BEGIN_STMT
ret_268 = gimplify_expr (_796, pre_p_252(D), post_p_253(D), _272, 1);
# DEBUG ret => ret_268
# DEBUG BEGIN_STMT
if (ret_268 == -2)
goto <bb 14>; [0.54%]
else
goto <bb 82>; [99.46%]
```
Command #2:
../stage1-gcc/xg++ -B../stage1-gcc/ -B/usr/x86_64-pc-linux-gnu/bin/ \
-nostdinc++ -B../stage1-x86_64-pc-linux-gnu/libstdc++-v3/src/.libs \
-B../stage1-x86_64-pc-linux-gnu/libstdc++-v3/libsupc++/.libs \
-I../stage1-x86_64-pc-linux-gnu/libstdc++-v3/include/x86_64-pc-linux-gnu \
-I../stage1-x86_64-pc-linux-gnu/libstdc++-v3/include \
-I../../libstdc++-v3/libsupc++ \
-L../stage1-x86_64-pc-linux-gnu/libstdc++-v3/src/.libs \
-L../stage1-x86_64-pc-linux-gnu/libstdc++-v3/libsupc++/.libs \
-fno-PIE -c -O3 -g -fno-checking -DIN_GCC -fno-exceptions \
-fno-rtti -fasynchronous-unwind-tables \
-W -Wall -Wno-narrowing -Wwrite-strings -Wcast-qual \
-Wmissing-format-attribute -Wconditionally-supported \
-Woverloaded-virtual -pedantic -Wno-long-long -Wno-variadic-macros \
-Wno-overlength-strings -fno-common -DHAVE_CONFIG_H -fno-PIE \
-I../stage2-gcc -I../../gcc -I../../gcc/. -I../../gcc/../include \
-I../../gcc/../libcpp/include -I../../gcc/../libcody \
-I../../gcc/../libdecnumber -I../../gcc/../libdecnumber/bid \
-I../libdecnumber -I../../gcc/../libbacktrace \
-o gimplify.o ../../gcc/gimplify.cc
Output.
```
<bb 83> [local count: 302659226]:
# _274 = PHI <is_gimple_reg_rhs_or_call(82), is_gimple_mem_rhs_or_call(81)>
# DEBUG lhs => NULL
# DEBUG final_pred => _274
# DEBUG BEGIN_STMT
# DEBUG BEGIN_STMT
ret_270 = gimplify_expr (_723, pre_p_253(D), post_p_254(D), _274, 1);
# DEBUG ret => ret_270
# DEBUG BEGIN_STMT
if (ret_270 == -2)
goto <bb 16>; [0.54%]
else
goto <bb 84>; [99.46%]
<bb 84> [local count: 301785333]:
# DEBUG BEGIN_STMT
_66 = MEM[(union tree_node * *)_1 + 32B];
_67 = _66->base.code;
if (_67 == 163)
goto <bb 85>; [34.00%]
else
goto <bb 90>; [66.00%]
```
Is this helpful enough to narrow it down?
