https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114121
--- Comment #9 from Richard Biener <rguenth at gcc dot gnu.org> --- Which of course would regress something like int a[16]; int foo (int i) { if (i > 7) return a[i]; else return a[i]; } where we'd no longer hoist as we no longer would value-number the refs the same (that extends to any ref using SSA names with eventually differing ranges). Reverting r9-398 likely isn't the best answer either, it would of course also regress the two valid replacements with zero (the prototype patch preserves those). There's the PR100923 fix (r12-1295-g7a56d3d3e99cc7) which targeted a similar (but even more odd) case with "contextual" PTA info (though there's really no such thing). But it didn't really fix the contextual thing but added re-valueization which in case of vn_reference_lookup_pieces works on value-numbered refs where failure mode is keeping the value-number. The prototype (after fixing it a bit) passes bootstrap but regresses quite some number of testcases (maybe due to ???s present). FAIL: g++.dg/ipa/devirt-20.C -std=gnu++98 scan-tree-dump-not release_ssa "abor t" FAIL: g++.dg/ipa/devirt-20.C -std=gnu++14 scan-tree-dump-not release_ssa "abor t" FAIL: g++.dg/ipa/devirt-20.C -std=gnu++17 scan-tree-dump-not release_ssa "abor t" FAIL: g++.dg/ipa/devirt-20.C -std=gnu++20 scan-tree-dump-not release_ssa "abort" FAIL: g++.dg/opt/pr110879.C -std=gnu++14 scan-tree-dump-not optimized "=\\\\s*\\\\S*res_(?!\\\\S*_M_end_of_storage;)" FAIL: g++.dg/opt/pr110879.C -std=gnu++17 scan-tree-dump-not optimized "=\\\\s*\\\\S*res_(?!\\\\S*_M_end_of_storage;)" FAIL: g++.dg/opt/pr110879.C -std=gnu++20 scan-tree-dump-not optimized "=\\\\s*\\\\S*res_(?!\\\\S*_M_end_of_storage;)" FAIL: g++.dg/pr99966.C -std=gnu++17 scan-tree-dump-not vrp1 "throw" FAIL: g++.dg/pr99966.C -std=gnu++20 scan-tree-dump-not vrp1 "throw" FAIL: g++.dg/vect/pr112961.cc -std=c++98 scan-tree-dump vect "LOOP VECTORIZED" FAIL: g++.dg/vect/pr112961.cc -std=c++14 scan-tree-dump vect "LOOP VECTORIZED" FAIL: g++.dg/vect/pr112961.cc -std=c++17 scan-tree-dump vect "LOOP VECTORIZED" FAIL: g++.dg/vect/pr112961.cc -std=c++20 scan-tree-dump vect "LOOP VECTORIZED" FAIL: g++.dg/vect/pr89653.cc -std=c++98 scan-tree-dump vect "vectorized 1 loops" FAIL: g++.dg/vect/pr89653.cc -std=c++14 scan-tree-dump vect "vectorized 1 loops" FAIL: g++.dg/vect/pr89653.cc -std=c++17 scan-tree-dump vect "vectorized 1 loops" FAIL: g++.dg/vect/pr89653.cc -std=c++20 scan-tree-dump vect "vectorized 1 loops" FAIL: g++.dg/vect/simd-10.cc -std=c++98 scan-tree-dump-times vect "vectorized [1-3] loops" 2 FAIL: g++.dg/vect/simd-10.cc -std=c++14 scan-tree-dump-times vect "vectorized [1-3] loops" 2 FAIL: g++.dg/vect/simd-10.cc -std=c++17 scan-tree-dump-times vect "vectorized [1-3] loops" 2 FAIL: g++.dg/vect/simd-10.cc -std=c++20 scan-tree-dump-times vect "vectorized [1-3] loops" 2 FAIL: gcc.dg/ira-loop-pressure.c scan-rtl-dump loop2_invariant "Decided to move invariant" FAIL: gcc.dg/pr41783.c scan-tree-dump pre "pretmp[^\\\\n]* = a_global_var;" FAIL: gcc.dg/pr78138.c (test for warnings, line 23) FAIL: gcc.dg/tree-ssa/ifc-pr69489-1.c scan-tree-dump-times ifcvt "Applying if-conversion" 1 FAIL: gcc.dg/tree-ssa/ifc-pr69489-1.c scan-tree-dump-times ifcvt "Invalid sum of outgoing probabilities 200.0" 1 FAIL: gcc.dg/tree-ssa/ifc-pr69489-1.c scan-tree-dump-times ifcvt "Invalid sum of incoming counts" 1 FAIL: gcc.dg/tree-ssa/ifc-pr69489-2.c scan-tree-dump-times ifcvt "Applying if-conversion" 1 FAIL: gcc.dg/tree-ssa/ifc-pr69489-2.c scan-tree-dump-times ifcvt "Invalid sum of outgoing probabilities 200.0" 1 FAIL: gcc.dg/tree-ssa/ifc-pr69489-2.c scan-tree-dump-times ifcvt "Invalid sum of incoming counts" 1 FAIL: gcc.dg/tree-ssa/loadpre1.c scan-tree-dump-times pre "Eliminated: 1" 1 FAIL: gcc.dg/tree-ssa/loadpre10.c scan-tree-dump-times pre "Eliminated: 1" 1 FAIL: gcc.dg/tree-ssa/loadpre11.c scan-tree-dump-times pre "Eliminated: 1" 1 FAIL: gcc.dg/tree-ssa/loadpre12.c scan-tree-dump-times pre "Eliminated: 1" 1 FAIL: gcc.dg/tree-ssa/loadpre13.c scan-tree-dump-times pre "Eliminated: 1" 1 FAIL: gcc.dg/tree-ssa/loadpre14.c scan-tree-dump-times pre "Eliminated: 2" 1 FAIL: gcc.dg/tree-ssa/loadpre16.c scan-tree-dump-times pre "Eliminated: 1" 1 FAIL: gcc.dg/tree-ssa/loadpre2.c scan-tree-dump-times pre "Eliminated: 1" 1 FAIL: gcc.dg/tree-ssa/loadpre21.c scan-tree-dump-times pre "Eliminated: 1" 1 FAIL: gcc.dg/tree-ssa/loadpre23.c scan-tree-dump-times pre "Eliminated: 1" 1 FAIL: gcc.dg/tree-ssa/loadpre24.c scan-tree-dump-times pre "Eliminated: 1" 1 FAIL: gcc.dg/tree-ssa/loadpre25.c scan-tree-dump-times pre "Eliminated: 1" 1 FAIL: gcc.dg/tree-ssa/loadpre3.c scan-tree-dump-times pre "Eliminated: 2" 1 FAIL: gcc.dg/tree-ssa/loadpre4.c scan-tree-dump-times pre "Eliminated: 1" 1 FAIL: gcc.dg/tree-ssa/loadpre6.c scan-tree-dump-times pre "Eliminated: 1" 1 FAIL: gcc.dg/tree-ssa/loadpre6.c scan-tree-dump-times pre "Insertions: 1" 1 FAIL: gcc.dg/tree-ssa/pr21417.c scan-tree-dump-times thread2 "jump thread" 1 FAIL: gcc.dg/tree-ssa/pr23455.c scan-tree-dump-times pre "Eliminated: 3" 1 FAIL: gcc.dg/tree-ssa/pr35286.c scan-tree-dump-times pre "Eliminated: 2" 1 FAIL: gcc.dg/tree-ssa/pr35287.c scan-tree-dump-times pre "Eliminated: 3" 1 FAIL: gcc.dg/tree-ssa/pr43491.c scan-tree-dump-times optimized "= data_0;" 1 FAIL: gcc.dg/tree-ssa/pr47392.c scan-tree-dump pre "Eliminated: 1" FAIL: gcc.dg/tree-ssa/predcom-1.c scan-tree-dump-times pcom "looparound ref" 1 FAIL: gcc.dg/tree-ssa/ssa-fre-45.c scan-tree-dump fre1 "return y_\\\\d+\\\\(D\\\\);" FAIL: gcc.dg/tree-ssa/ssa-hoist-4.c scan-tree-dump-times optimized "= \\\\*" 2 FAIL: gcc.dg/tree-ssa/ssa-hoist-4.c scan-tree-dump-times optimized "MAX_EXPR" 1 FAIL: gcc.dg/tree-ssa/ssa-hoist-8.c scan-tree-dump pre "HOIST inserted: 1" FAIL: gcc.dg/tree-ssa/ssa-hoist-8.c scan-tree-dump-times pre " = mem;" 1 FAIL: gcc.dg/tree-ssa/ssa-hoist-9.c scan-tree-dump pre "HOIST inserted: 3" FAIL: gcc.dg/tree-ssa/ssa-hoist-9.c scan-tree-dump-times pre " = \\\\*" 2 FAIL: gcc.dg/tree-ssa/ssa-hoist-9.c scan-tree-dump-times pre " = [^\\r\\n]* \\\\+ [^\\r\\n]*;" 1 FAIL: gcc.dg/tree-ssa/ssa-pre-16.c scan-tree-dump-times pre "Eliminated: 1" 1 FAIL: gcc.dg/tree-ssa/ssa-pre-17.c scan-tree-dump pre "Eliminated: 1" FAIL: gcc.dg/tree-ssa/ssa-pre-19.c scan-tree-dump pre "Eliminated: 3" FAIL: gcc.dg/tree-ssa/ssa-pre-20.c scan-tree-dump pre "New PHIs: 2" FAIL: gcc.dg/tree-ssa/ssa-pre-21.c scan-tree-dump-times pre "= \\\\*[^\\n;]*;" 2 FAIL: gcc.dg/tree-ssa/ssa-pre-23.c scan-tree-dump pre "Eliminated: 3" FAIL: gcc.dg/tree-ssa/ssa-pre-25.c scan-tree-dump pre "Eliminated: 1" FAIL: gcc.dg/tree-ssa/ssa-pre-29.c scan-tree-dump pre "Replaced hoist" FAIL: gcc.dg/tree-ssa/ssa-pre-30.c scan-tree-dump-times pre "Replaced MEM" 3 FAIL: gcc.dg/tree-ssa/ssa-pre-34.c scan-tree-dump pre "Insertions: 1" FAIL: gcc.dg/tree-ssa/ssa-pre-34.c scan-tree-dump pre "HOIST inserted: 1" FAIL: gcc.dg/tree-ssa/ssa-pre-34.c scan-tree-dump pre "Eliminated: 3" FAIL: gcc.dg/tree-ssa/ssa-pre-34.c scan-tree-dump-not optimized "foo" FAIL: gcc.dg/vect/bb-slp-57.c -flto -ffat-lto-objects scan-tree-dump-times slp1 "transform load" 1 FAIL: gcc.dg/vect/bb-slp-57.c scan-tree-dump-times slp1 "transform load" 1 FAIL: gcc.dg/vect/pr56625.c scan-tree-dump-times vect "vectorized 1 loops" 1 ...