[globalisel][tablegen] Enable the import of rules involving fma.

Summary:
G_FMA was recently added to GlobalISel which enables the import of rules
involving fma. Add the mapping to allow it.

Reviewers: ab, t.p.northover, qcolombet, rovka, aditya_nandakumar

Reviewed By: rovka

Subscribers: kristof.beyls, javed.absar, igorb, llvm-commits

Differential Revision: https://reviews.llvm.org/D35130

llvm-svn: 308308

llvm/include/llvm/Target/GlobalISel/SelectionDAGCompat.td

@@ -58,6 +58,7 @@ def : GINodeEquiv<G_SITOFP, sint_to_fp>;
 def : GINodeEquiv<G_UITOFP, uint_to_fp>;
 def : GINodeEquiv<G_FADD, fadd>;
 def : GINodeEquiv<G_FSUB, fsub>;
+def : GINodeEquiv<G_FMA, fma>;
 def : GINodeEquiv<G_FMUL, fmul>;
 def : GINodeEquiv<G_FDIV, fdiv>;
 def : GINodeEquiv<G_FREM, frem>;

llvm/lib/Target/AArch64/AArch64LegalizerInfo.cpp

@@ -82,7 +82,7 @@ AArch64LegalizerInfo::AArch64LegalizerInfo() {
     setAction({Op, 1, s1}, Legal);
   }
 
-  for (unsigned BinOp : {G_FADD, G_FSUB, G_FMUL, G_FDIV})
+  for (unsigned BinOp : {G_FADD, G_FSUB, G_FMA, G_FMUL, G_FDIV})
     for (auto Ty : {s32, s64})
       setAction({BinOp, Ty}, Legal);
 

llvm/test/CodeGen/AArch64/GlobalISel/select-fma.mir

@@ -0,0 +1,41 @@
+# RUN: llc -O0 -mtriple=aarch64-- -run-pass=instruction-select -verify-machineinstrs -global-isel %s -o - | FileCheck %s
+
+--- |
+  target datalayout = "e-m:o-i64:64-i128:128-n32:64-S128"
+
+  define void @FMADDSrrr_fpr() { ret void }
+...
+
+---
+# CHECK-LABEL: name: FMADDSrrr_fpr
+name:            FMADDSrrr_fpr
+legalized:       true
+regBankSelected: true
+
+# CHECK:      registers:
+# CHECK-NEXT:  - { id: 0, class: fpr32, preferred-register: '' }
+# CHECK-NEXT:  - { id: 1, class: fpr32, preferred-register: '' }
+# CHECK-NEXT:  - { id: 2, class: fpr32, preferred-register: '' }
+# CHECK-NEXT:  - { id: 3, class: fpr32, preferred-register: '' }
+registers:
+  - { id: 0, class: fpr }
+  - { id: 1, class: fpr }
+  - { id: 2, class: fpr }
+  - { id: 3, class: fpr }
+
+# CHECK:  body:
+# CHECK:    %0 = COPY %w0
+# CHECK:    %1 = COPY %w1
+# CHECK:    %2 = COPY %w2
+# CHECK:    %3 = FMADDSrrr %0, %1, %2
+body:             |
+  bb.0:
+    liveins: %w0, %w1, %w2
+
+    %0(s32) = COPY %w0
+    %1(s32) = COPY %w1
+    %2(s32) = COPY %w2
+    %3(s32) = G_FMA %0, %1, %2
+    %x0 = COPY %3
+...
+