On Mon, 2020-07-13 at 06:42 -0700, H.J. Lu via Gcc-patches wrote: > Change CTZ_DEFINED_VALUE_AT_ZERO/CTZ_DEFINED_VALUE_AT_ZERO to return 0/2 > to enable table-based clz/ctz optimization: > > -- Macro: CLZ_DEFINED_VALUE_AT_ZERO (MODE, VALUE) > -- Macro: CTZ_DEFINED_VALUE_AT_ZERO (MODE, VALUE) > A C expression that indicates whether the architecture defines a > value for 'clz' or 'ctz' with a zero operand. A result of '0' > indicates the value is undefined. If the value is defined for only > the RTL expression, the macro should evaluate to '1'; if the value > applies also to the corresponding optab entry (which is normally > the case if it expands directly into the corresponding RTL), then > the macro should evaluate to '2'. In the cases where the value is > defined, VALUE should be set to this value. > > gcc/ > > PR target/95863 > * config/i386/i386.h (CTZ_DEFINED_VALUE_AT_ZERO): Return 0/2. > (CLZ_DEFINED_VALUE_AT_ZERO): Likewise. > > gcc/testsuite/ > > PR target/95863 > * gcc.target/i386/pr95863-1.c: New test. > * gcc.target/i386/pr95863-2.c: Likewise. OK jeff >
