llvm-6502/lib/CodeGen/SelectionDAG
Chris Lattner 5a09690446 Implement a signficant optimization for inline asm:
When choosing between constraints with multiple options,
like "ir", test to see if we can use the 'i' constraint and
go with that if possible.  This produces more optimal ASM in
all cases (sparing a register and an instruction to load it),
and fixes inline asm like this:

void test () {
  asm volatile (" %c0 %1 " : : "imr" (42), "imr"(14));
}

Previously we would dump "42" into a memory location (which
is ok for the 'm' constraint) which would cause a problem
because the 'c' modifier is not valid on memory operands.

Isn't it great how inline asm turns 'missed optimization'
into 'compile failed'??

Incidentally, this was the todo in 
PowerPC/2007-04-24-InlineAsm-I-Modifier.ll

Please do NOT pull this into Tak.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@50315 91177308-0d34-0410-b5e6-96231b3b80d8
2008-04-27 00:37:18 +00:00
..
CallingConvLower.cpp
DAGCombiner.cpp
LegalizeDAG.cpp Pull the code to perform an INSERT_VECTOR_ELT in memory out into its own 2008-04-25 18:07:40 +00:00
LegalizeTypes.cpp
LegalizeTypes.h
LegalizeTypesExpand.cpp
LegalizeTypesFloatToInt.cpp
LegalizeTypesPromote.cpp
LegalizeTypesScalarize.cpp
LegalizeTypesSplit.cpp
Makefile
ScheduleDAG.cpp
ScheduleDAGList.cpp
ScheduleDAGRRList.cpp
SelectionDAG.cpp
SelectionDAGISel.cpp Implement a signficant optimization for inline asm: 2008-04-27 00:37:18 +00:00
SelectionDAGPrinter.cpp Fix an out-of-bounds access in -view-sunit-dags in the case of an 2008-04-21 20:07:30 +00:00
TargetLowering.cpp Implement a signficant optimization for inline asm: 2008-04-27 00:37:18 +00:00