- Add pseudo instructions tLDRpci_pic and t2LDRpci_pic which does a pc-relative
load of a GV from constantpool and then add pc. It allows the code sequence to
be rematerializable so it would be hoisted by machine licm.
- Add a late pass to break these pseudo instructions into a number of real
instructions. Also move the code in Thumb2 IT pass that breaks up t2MOVi32imm
to this pass. This is done before post regalloc scheduling to allow the
scheduler to proper schedule these instructions. It also allow them to be
if-converted and shrunk by later passes.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86304 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/ARM/ARMInstrThumb.td b/lib/Target/ARM/ARMInstrThumb.td
index 5d02925..2796364 100644
--- a/lib/Target/ARM/ARMInstrThumb.td
+++ b/lib/Target/ARM/ARMInstrThumb.td
@@ -740,3 +740,13 @@
def : T1Pat<(i32 imm0_255_comp:$src),
(tMVN (tMOVi8 (imm_comp_XFORM imm:$src)))>;
+
+// Pseudo instruction that combines ldr from constpool and add pc. This should
+// be expanded into two instructions late to allow if-conversion and
+// scheduling.
+let isReMaterializable = 1 in
+def tLDRpci_pic : PseudoInst<(outs GPR:$dst), (ins i32imm:$addr, pclabel:$cp),
+ NoItinerary, "@ ldr.n\t$dst, $addr\n$cp:\n\tadd\t$dst, pc",
+ [(set GPR:$dst, (ARMpic_add (load (ARMWrapper tconstpool:$addr)),
+ imm:$cp))]>,
+ Requires<[IsThumb1Only]>;