gcc/ChangeLog:
PR tree-optimization/42078
* gimple.h (gimple_replace_lhs): New declaration.
* gimple.c (gimple_replace_lhs): New function.
* tree-ssa-math-opts.c (execute_cse_reciprocals): Call it before
modifying the call.
gcc/testsuite/ChangeLog:
PR tree-optimization/42078
* gcc.dg/pr42078.c: New test.

From-SVN: r154400