[llvm] b383753 - [GIsel] Add missing libcall for G_MUL to LegalizerHelper

[Kai Nacke via llvm-commits]

Author: Kai Nacke
Date: 2022-08-02T13:35:25-04:00
New Revision: b38375378dea604b8957f35d6c8a128c63c971d9

URL: https://github.com/llvm/llvm-project/commit/b38375378dea604b8957f35d6c8a128c63c971d9
DIFF: https://github.com/llvm/llvm-project/commit/b38375378dea604b8957f35d6c8a128c63c971d9.diff

LOG: [GIsel] Add missing libcall for G_MUL to LegalizerHelper

The LegalizerHelper misses the code to lower G_MUL to a library call,
which this change adds.

Reviewed By: arsenm

Differential Revision: https://reviews.llvm.org/D130987

Added: 
    

Modified: 
    llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
    llvm/unittests/CodeGen/GlobalISel/LegalizerHelperTest.cpp

Removed: 
    


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diff  --git a/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp b/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
index 52ee13757f276..ddd846c79cd19 100644
--- a/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
+++ b/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
@@ -497,6 +497,8 @@ static RTLIB::Libcall getRTLibDesc(unsigned Opcode, unsigned Size) {
   } while (0)
 
   switch (Opcode) {
+  case TargetOpcode::G_MUL:
+    RTLIBCASE_INT(MUL_I);
   case TargetOpcode::G_SDIV:
     RTLIBCASE_INT(SDIV_I);
   case TargetOpcode::G_UDIV:
@@ -795,6 +797,7 @@ LegalizerHelper::libcall(MachineInstr &MI, LostDebugLocObserver &LocObserver) {
   switch (MI.getOpcode()) {
   default:
     return UnableToLegalize;
+  case TargetOpcode::G_MUL:
   case TargetOpcode::G_SDIV:
   case TargetOpcode::G_UDIV:
   case TargetOpcode::G_SREM:

diff  --git a/llvm/unittests/CodeGen/GlobalISel/LegalizerHelperTest.cpp b/llvm/unittests/CodeGen/GlobalISel/LegalizerHelperTest.cpp
index 2f0c00db9c159..4f3750c15cfdc 100644
--- a/llvm/unittests/CodeGen/GlobalISel/LegalizerHelperTest.cpp
+++ b/llvm/unittests/CodeGen/GlobalISel/LegalizerHelperTest.cpp
@@ -2136,6 +2136,64 @@ TEST_F(AArch64GISelMITest, LibcallSimple) {
             Helper.libcall(*MIBFADD, DummyLocObserver));
 }
 
+TEST_F(AArch64GISelMITest, LibcallMul) {
+  setUp();
+  if (!TM)
+    return;
+
+  // Declare your legalization info
+  DefineLegalizerInfo(A, {
+    getActionDefinitionsBuilder(G_MUL).libcallFor({s32, s64, s128});
+  });
+
+  LLT S32{LLT::scalar(32)};
+  LLT S64{LLT::scalar(64)};
+  LLT S128{LLT::scalar(128)};
+  auto MIBTrunc = B.buildTrunc(S32, Copies[0]);
+  auto MIBExt = B.buildAnyExt(S128, Copies[0]);
+
+  auto MIBMul32 =
+      B.buildInstr(TargetOpcode::G_MUL, {S32}, {MIBTrunc, MIBTrunc});
+  auto MIBMul64 =
+      B.buildInstr(TargetOpcode::G_MUL, {S64}, {Copies[0], Copies[0]});
+  auto MIBMul128 =
+      B.buildInstr(TargetOpcode::G_MUL, {S128}, {MIBExt, MIBExt});
+
+  AInfo Info(MF->getSubtarget());
+  DummyGISelObserver Observer;
+  LostDebugLocObserver DummyLocObserver("");
+  LegalizerHelper Helper(*MF, Info, Observer, B);
+
+  EXPECT_EQ(LegalizerHelper::LegalizeResult::Legalized,
+            Helper.libcall(*MIBMul32, DummyLocObserver));
+  EXPECT_EQ(LegalizerHelper::LegalizeResult::Legalized,
+            Helper.libcall(*MIBMul64, DummyLocObserver));
+  EXPECT_EQ(LegalizerHelper::LegalizeResult::Legalized,
+            Helper.libcall(*MIBMul128, DummyLocObserver));
+
+  auto CheckStr = R"(
+  CHECK: [[COPY:%[0-9]+]]:_(s64) = COPY
+  CHECK: [[TRUNC:%[0-9]+]]:_(s32) = G_TRUNC
+  CHECK: [[ANYEXT:%[0-9]+]]:_(s128) = G_ANYEXT
+  CHECK: $w0 = COPY [[TRUNC]]
+  CHECK: $w1 = COPY [[TRUNC]]
+  CHECK: BL &__mulsi3
+  CHECK: $x0 = COPY [[COPY]]
+  CHECK: $x1 = COPY [[COPY]]
+  CHECK: BL &__muldi3
+  CHECK: [[UV:%[0-9]+]]:_(s64), [[UV1:%[0-9]+]]:_(s64) = G_UNMERGE_VALUES [[ANYEXT]]
+  CHECK: [[UV2:%[0-9]+]]:_(s64), [[UV3:%[0-9]+]]:_(s64) = G_UNMERGE_VALUES [[ANYEXT]]
+  CHECK: $x0 = COPY [[UV]]
+  CHECK: $x1 = COPY [[UV1]]
+  CHECK: $x2 = COPY [[UV2]]
+  CHECK: $x3 = COPY [[UV3]]
+  CHECK: BL &__multi3
+  )";
+
+  // Check
+  EXPECT_TRUE(CheckMachineFunction(*MF, CheckStr)) << *MF;
+}
+
 TEST_F(AArch64GISelMITest, LibcallSRem) {
   setUp();
   if (!TM)