mirror of
https://github.com/RPCS3/llvm-mirror.git
synced 2024-10-22 20:43:44 +02:00
af95bf4558
Currently, @llvm.smul.with.overflow.i8 expands to 9 instructions, where 3 are really needed. This adds X86ISD::UMUL8/SMUL8 SD nodes, and custom lowers them to MUL8/IMUL8 + SETO. i8 is a special case because there is no two/three operand variants of (I)MUL8, so the first operand and return value need to go in AL/AX. Also, we can't write patterns for these instructions: TableGen refuses patterns where output operands don't match SDNode results. In this case, instructions where the output operand is an implicitly defined register. A related special case (and FIXME) exists for MUL8 (X86InstrArith.td): // FIXME: Used for 8-bit mul, ignore result upper 8 bits. // This probably ought to be moved to a def : Pat<> if the // syntax can be accepted. [(set AL, (mul AL, GR8:$src)), (implicit EFLAGS)] Ideally, these go away with UMUL8, but we still need to improve TableGen support of implicit operands in patterns. Before this change: movsbl %sil, %eax movsbl %dil, %ecx imull %eax, %ecx movb %cl, %al sarb $7, %al movzbl %al, %eax movzbl %ch, %esi cmpl %eax, %esi setne %al After: movb %dil, %al imulb %sil seto %al Also, remove a made-redundant testcase for PR19858, and enable more FastISel ALU-overflow tests for SelectionDAG too. Differential Revision: http://reviews.llvm.org/D5809 llvm-svn: 220516 |
||
|---|---|---|
| .. | ||
| AArch64 | ||
| ARM | ||
| CPP | ||
| Generic | ||
| Hexagon | ||
| Inputs | ||
| Mips | ||
| MSP430 | ||
| NVPTX | ||
| PowerPC | ||
| R600 | ||
| SPARC | ||
| SystemZ | ||
| Thumb | ||
| Thumb2 | ||
| X86 | ||
| XCore | ||