diff --git a/lib/Target/README.txt b/lib/Target/README.txt index 7f650ad9882..ba0b4433235 100644 --- a/lib/Target/README.txt +++ b/lib/Target/README.txt @@ -1307,6 +1307,9 @@ bb2: ; preds = %bb, %bb1 DSE should sink partially dead stores to get the store out of the loop. +Here's another partial dead case: +http://gcc.gnu.org/bugzilla/show_bug.cgi?id=12395 + //===---------------------------------------------------------------------===// Scalar PRE hoists the mul in the common block up to the else: @@ -1367,6 +1370,54 @@ bb3: ; preds = %bb1, %bb2, %bb %11 is fully redundant, an in BB2 it should have the value %8. +GCC PR33344 is a similar case. + //===---------------------------------------------------------------------===// +There are many load PRE testcases in testsuite/gcc.dg/tree-ssa/loadpre* in the +GCC testsuite. There are many pre testcases as ssa-pre-*.c + +Other simple load PRE cases: +http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35287 +http://gcc.gnu.org/bugzilla/show_bug.cgi?id=34677 (licm does this) +http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29789 (SPEC2K6) +http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23455 +http://gcc.gnu.org/bugzilla/show_bug.cgi?id=14705 + +//===---------------------------------------------------------------------===// + +When GVN/PRE finds a store of float* to a must aliases pointer when expecting +an int*, it should turn it into a bitcast. This is a nice generalization of +the SROA hack that would apply to other cases. + +One example (that requires crazy phi translation) is: +http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16799 + +//===---------------------------------------------------------------------===// + +A/B get pinned to the stack because we turn an if/then into a select instead +of PRE'ing the load/store. This may be fixable in instcombine: +http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37892 + +Interesting missed case because of control flow flattening (should be 2 loads): +http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26629 + + +//===---------------------------------------------------------------------===// + +http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19633 +We could eliminate the branch condition here, loading from null is undefined: + +struct S { int w, x, y, z; }; +struct T { int r; struct S s; }; +void bar (struct S, int); +void foo (int a, struct T b) +{ + struct S *c = 0; + if (a) + c = &b.s; + bar (*c, a); +} + +//===---------------------------------------------------------------------===//