[MIPS GlobalISel] NarrowScalar G_TRUNC
Add NarrowScalar for G_TRUNC when NarrowTy is half the size of source.
NarrowScalar G_TRUNC to s32 for MIPS32.
Differential Revision: https://reviews.llvm.org/D66202
llvm-svn: 369509
diff --git a/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp b/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
index 26c25ba..4622248 100644
--- a/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
+++ b/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
@@ -633,6 +633,21 @@
MI.eraseFromParent();
return Legalized;
}
+ case TargetOpcode::G_TRUNC: {
+ if (TypeIdx != 1)
+ return UnableToLegalize;
+
+ uint64_t SizeOp1 = MRI.getType(MI.getOperand(1).getReg()).getSizeInBits();
+ if (NarrowTy.getSizeInBits() * 2 != SizeOp1) {
+ LLVM_DEBUG(dbgs() << "Can't narrow trunc to type " << NarrowTy << "\n");
+ return UnableToLegalize;
+ }
+
+ auto Unmerge = MIRBuilder.buildUnmerge(NarrowTy, MI.getOperand(1).getReg());
+ MIRBuilder.buildCopy(MI.getOperand(0).getReg(), Unmerge.getReg(0));
+ MI.eraseFromParent();
+ return Legalized;
+ }
case TargetOpcode::G_ADD: {
// FIXME: add support for when SizeOp0 isn't an exact multiple of
diff --git a/llvm/lib/Target/Mips/MipsLegalizerInfo.cpp b/llvm/lib/Target/Mips/MipsLegalizerInfo.cpp
index 558af42..4564116 100644
--- a/llvm/lib/Target/Mips/MipsLegalizerInfo.cpp
+++ b/llvm/lib/Target/Mips/MipsLegalizerInfo.cpp
@@ -54,6 +54,10 @@
{s32, p0, 16, 8}})
.minScalar(0, s32);
+ getActionDefinitionsBuilder(G_TRUNC)
+ .legalIf([](const LegalityQuery &Query) { return false; })
+ .maxScalar(1, s32);
+
getActionDefinitionsBuilder(G_SELECT)
.legalForCartesianProduct({p0, s32, s64}, {s32})
.minScalar(0, s32)