[Bug middle-end/42181] [4.5 Regression][graphite] -fgraphite-identity miscompiles air.f90

[howarth at nitro dot med dot uc dot edu]

------- Comment #21 from howarth at nitro dot med dot uc dot edu  2010-03-09 03:48 -------
Interestingly, I get...

gfortran -fgraphite-identity -O3 -Wstrict-overflow=5 -c spectop.f90
spectop.f90: In function ‘spectop’:
spectop.f90:5:0: warning: assuming signed overflow does not occur when changing
X +- C1 cmp C2 to X cmp C1 +- C2
spectop.f90:5:0: warning: assuming signed overflow does not occur when changing
X +- C1 cmp C2 to X cmp C1 +- C2
spectop.f90:5:0: warning: assuming signed overflow does not occur when reducing
constant in comparison
spectop.f90:5:0: warning: assuming signed overflow does not occur when changing
X +- C1 cmp C2 to X cmp C1 +- C2
spectop.f90:5:0: warning: assuming signed overflow does not occur when changing
X +- C1 cmp C2 to X cmp C1 +- C2
spectop.f90:5:0: warning: assuming signed overflow does not occur when changing
X +- C1 cmp C2 to X cmp C1 +- C2
spectop.f90:5:0: warning: assuming signed overflow does not occur when changing
X +- C1 cmp C2 to X cmp C1 +- C2
spectop.f90:5:0: warning: assuming signed overflow does not occur when changing
X +- C1 cmp C2 to X cmp C1 +- C2

whereas without -fgraphite-identity, I get...

gfortran -O3 -Wstrict-overflow=5 -c spectop.f90
spectop.f90: In function ‘spectop’:
spectop.f90:23:0: warning: assuming signed overflow does not occur when
changing X +- C1 cmp C2 to X cmp C1 +- C2


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42181