[PATCH] D15438: Do not ASSERTZEXT for i16 result of bitcast from f16 operand

[Pirama Arumuga Nainar via llvm-commits]

pirama created this revision.
pirama added reviewers: ab, jmolloy.
pirama added subscribers: llvm-commits, srhines.

During legalization if i16, do not ASSERTZEXT the result of FP_TO_FP16.
Directly return an FP_TO_FP16 node with return type as the
promote-to-type of i16.

This patch also removes extraneous length check.  This legalization
should be valid even if integer and float types are of different
lengths.

This patch breaks a hard-float test for fp16 args.  The test is changed
to allow a vmov to zero-out the top bits, and also ensure that the
return value is in an FP register.

http://reviews.llvm.org/D15438

Files:
  lib/CodeGen/SelectionDAG/LegalizeIntegerTypes.cpp
  test/CodeGen/ARM/fp16-args.ll
  test/CodeGen/ARM/fp16-v3.ll

Index: test/CodeGen/ARM/fp16-v3.ll
===================================================================
--- /dev/null
+++ test/CodeGen/ARM/fp16-v3.ll
@@ -0,0 +1,28 @@
+; RUN: llc -mattr=+fp16 < %s | FileCheck %s --check-prefix=CHECK
+
+target datalayout = "e-m:e-p:32:32-i64:64-v128:64:128-a:0:32-n32-S64"
+target triple = "armv7a--none-eabi"
+
+; CHECK-LABEL: test_vec3:
+; CHECK: vcvtb.f32.f16
+; CHECK: vcvt.f32.s32
+; CHECK: vadd.f32
+; CHECK-NEXT: vcvtb.f16.f32 [[SREG:s[0-9]+]], {{.*}}
+; CHECK-NEXT: vmov [[RREG1:r[0-9]+]], [[SREG]]
+; CHECK-NEXT: uxth [[RREG2:r[0-9]+]], [[RREG1]]
+; CHECK-NEXT: pkhbt [[RREG3:r[0-9]+]], [[RREG1]], [[RREG1]], lsl #16
+; CHECK-DAG: strh [[RREG1]], [r0, #4]
+; CHECK-DAG: vmov [[DREG:d[0-9]+]], [[RREG3]], [[RREG2]]
+; CHECK-DAG: vst1.32 {[[DREG]][0]}, [r0:32]
+; CHECK-NEXT: bx lr
+define void @test_vec3(<3 x half>* %arr, i32 %i) #0 {
+  %H = sitofp i32 %i to half
+  %S = fadd half %H, 0xH4A00
+  %1 = insertelement <3 x half> undef, half %S, i32 0
+  %2 = insertelement <3 x half> %1, half %S, i32 1
+  %3 = insertelement <3 x half> %2, half %S, i32 2
+  store <3 x half> %3, <3 x half>* %arr, align 8
+  ret void
+}
+
+attributes #0 = { nounwind }
Index: test/CodeGen/ARM/fp16-args.ll
===================================================================
--- test/CodeGen/ARM/fp16-args.ll
+++ test/CodeGen/ARM/fp16-args.ll
@@ -32,9 +32,10 @@
 ; HARD: vcvtb.f32.f16   {{s[0-9]+}}, s1
 ; HARD: vcvtb.f32.f16   {{s[0-9]+}}, s0
 ; HARD: vadd.f32        {{s[0-9]+}}, {{s[0-9]+}}, {{s[0-9]+}}
-; HARD: vcvtb.f16.f32   s0, {{s[0-9]+}}
-; HARD-NOT: vmov
-; HARD-NOT: uxth
+; HARD: vcvtb.f16.f32   [[SREG:s[0-9]+]], {{s[0-9]+}}
+; HARD-NEXT: vmov            [[REG0:r[0-9]+]], [[SREG]]
+; HARD-NEXT: uxth            [[REG1:r[0-9]+]], [[REG0]]
+; HARD-NEXT: vmov            s0, [[REG1]]
 
 ; CHECK: bx lr
 }
Index: lib/CodeGen/SelectionDAG/LegalizeIntegerTypes.cpp
===================================================================
--- lib/CodeGen/SelectionDAG/LegalizeIntegerTypes.cpp
+++ lib/CodeGen/SelectionDAG/LegalizeIntegerTypes.cpp
@@ -262,12 +262,8 @@
     return DAG.getNode(ISD::ANY_EXTEND, dl, NOutVT, GetSoftenedFloat(InOp));
   case TargetLowering::TypePromoteFloat: {
     // Convert the promoted float by hand.
-    if (NOutVT.bitsEq(NInVT)) {
-      SDValue PromotedOp = GetPromotedFloat(InOp);
-      SDValue Trunc = DAG.getNode(ISD::FP_TO_FP16, dl, NOutVT, PromotedOp);
-      return DAG.getNode(ISD::AssertZext, dl, NOutVT, Trunc,
-                         DAG.getValueType(OutVT));
-    }
+    SDValue PromotedOp = GetPromotedFloat(InOp);
+    return DAG.getNode(ISD::FP_TO_FP16, dl, NOutVT, PromotedOp);
     break;
   }
   case TargetLowering::TypeExpandInteger:


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