diff options
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/Target/X86/X86InstrCompiler.td | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/lib/Target/X86/X86InstrCompiler.td b/lib/Target/X86/X86InstrCompiler.td index 724e6b895e..da5e05a5d7 100644 --- a/lib/Target/X86/X86InstrCompiler.td +++ b/lib/Target/X86/X86InstrCompiler.td @@ -207,6 +207,12 @@ def : Pat<(i32 (sext (i8 (X86setcc_c X86_COND_B, EFLAGS)))), def : Pat<(i64 (sext (i8 (X86setcc_c X86_COND_B, EFLAGS)))), (SETB_C64r)>; +// We canonicalize 'setb' to "(and (sbb reg,reg), 1)" on the hope that the and +// will be eliminated and that the sbb can be extended up to a wider type. When +// this happens, it is great. However, if we are left with an 8-bit sbb and an +// and, we might as well just match it as a setb. +def : Pat<(and (i8 (X86setcc_c X86_COND_B, EFLAGS)), 1), + (SETBr)>; //===----------------------------------------------------------------------===// // String Pseudo Instructions |