[llvm] 1379740 - [NVPTX] Fix segfault with i128 types in arrays (#120562)

[via llvm-commits]

Author: Valery Chernov
Date: 2025-01-13T12:49:34-08:00
New Revision: 137974002d0f395e9e6e7cb54403c2ed760433a6

URL: https://github.com/llvm/llvm-project/commit/137974002d0f395e9e6e7cb54403c2ed760433a6
DIFF: https://github.com/llvm/llvm-project/commit/137974002d0f395e9e6e7cb54403c2ed760433a6.diff

LOG: [NVPTX] Fix segfault with i128 types in arrays (#120562)

- Process i128 array with custom ComputePTXValueVTs. The i128 elements
should be handled and split into i64 types in the recursion.
- Add corresponding tests

Added: 
    llvm/test/CodeGen/NVPTX/i128-array.ll

Modified: 
    llvm/lib/Target/NVPTX/NVPTXISelLowering.cpp

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Target/NVPTX/NVPTXISelLowering.cpp b/llvm/lib/Target/NVPTX/NVPTXISelLowering.cpp
index 5c1f717694a4c7..208d724f7ae283 100644
--- a/llvm/lib/Target/NVPTX/NVPTXISelLowering.cpp
+++ b/llvm/lib/Target/NVPTX/NVPTXISelLowering.cpp
@@ -261,6 +261,15 @@ static void ComputePTXValueVTs(const TargetLowering &TLI, const DataLayout &DL,
     return;
   }
 
+  // Given an array type, recursively traverse the elements with custom ComputePTXValueVTs.
+  if (ArrayType *ATy = dyn_cast<ArrayType>(Ty)) {
+    Type *EltTy = ATy->getElementType();
+    uint64_t EltSize = DL.getTypeAllocSize(EltTy);
+    for (int I : llvm::seq<int>(ATy->getNumElements()))
+      ComputePTXValueVTs(TLI, DL, EltTy, ValueVTs, Offsets, StartingOffset + I * EltSize);
+    return;
+  }
+
   ComputeValueVTs(TLI, DL, Ty, TempVTs, &TempOffsets, StartingOffset);
   for (unsigned i = 0, e = TempVTs.size(); i != e; ++i) {
     EVT VT = TempVTs[i];

diff  --git a/llvm/test/CodeGen/NVPTX/i128-array.ll b/llvm/test/CodeGen/NVPTX/i128-array.ll
new file mode 100644
index 00000000000000..348df8dcc73735
--- /dev/null
+++ b/llvm/test/CodeGen/NVPTX/i128-array.ll
@@ -0,0 +1,68 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py UTC_ARGS: --version 5
+; RUN: llc < %s -O0 -march=nvptx64 -mcpu=sm_20 | FileCheck %s
+
+define [2 x i128] @foo(i64 %a, i32 %b) {
+; CHECK-LABEL: foo(
+; CHECK:       {
+; CHECK-NEXT:    .reg .b32 %r<2>;
+; CHECK-NEXT:    .reg .b64 %rd<5>;
+; CHECK-EMPTY:
+; CHECK-NEXT:  // %bb.0:
+; CHECK-NEXT:    ld.param.u32 %r1, [foo_param_1];
+; CHECK-NEXT:    ld.param.u64 %rd1, [foo_param_0];
+; CHECK-NEXT:    shr.s64 %rd2, %rd1, 63;
+; CHECK-NEXT:    cvt.s64.s32 %rd3, %r1;
+; CHECK-NEXT:    shr.s64 %rd4, %rd3, 63;
+; CHECK-NEXT:    st.param.v2.b64 [func_retval0], {%rd1, %rd2};
+; CHECK-NEXT:    st.param.v2.b64 [func_retval0+16], {%rd3, %rd4};
+; CHECK-NEXT:    ret;
+  %1 = sext i64 %a to i128
+  %2 = sext i32 %b to i128
+  %3 = insertvalue [2 x i128] undef, i128 %1, 0
+  %4 = insertvalue [2 x i128] %3, i128 %2, 1
+
+  ret [2 x i128] %4
+}
+
+define [2 x i128] @foo2(ptr byval([2 x i128]) %a) {
+; CHECK-LABEL: foo2(
+; CHECK:       {
+; CHECK-NEXT:    .reg .b64 %rd<6>;
+; CHECK-EMPTY:
+; CHECK-NEXT:  // %bb.0:
+; CHECK-NEXT:    mov.b64 %rd1, foo2_param_0;
+; CHECK-NEXT:    ld.param.u64 %rd2, [foo2_param_0+8];
+; CHECK-NEXT:    ld.param.u64 %rd3, [foo2_param_0];
+; CHECK-NEXT:    ld.param.u64 %rd4, [foo2_param_0+24];
+; CHECK-NEXT:    ld.param.u64 %rd5, [foo2_param_0+16];
+; CHECK-NEXT:    st.param.v2.b64 [func_retval0], {%rd3, %rd2};
+; CHECK-NEXT:    st.param.v2.b64 [func_retval0+16], {%rd5, %rd4};
+; CHECK-NEXT:    ret;
+  %ptr0 = getelementptr [2 x i128], ptr %a, i64 0, i32 0
+  %1 = load i128, i128* %ptr0
+  %ptr1 = getelementptr [2 x i128], ptr %a, i64 0, i32 1
+  %2 = load i128, i128* %ptr1
+  %3 = insertvalue [2 x i128] undef, i128 %1, 0
+  %4 = insertvalue [2 x i128] %3, i128 %2, 1
+
+  ret [2 x i128] %4
+}
+
+define [2 x i128] @foo3([2 x i128] %a) {
+; CHECK-LABEL: foo3(
+; CHECK:       {
+; CHECK-NEXT:    .reg .b64 %rd<5>;
+; CHECK-EMPTY:
+; CHECK-NEXT:  // %bb.0:
+; CHECK-NEXT:    ld.param.v2.u64 {%rd3, %rd4}, [foo3_param_0+16];
+; CHECK-NEXT:    ld.param.v2.u64 {%rd1, %rd2}, [foo3_param_0];
+; CHECK-NEXT:    st.param.v2.b64 [func_retval0], {%rd1, %rd2};
+; CHECK-NEXT:    st.param.v2.b64 [func_retval0+16], {%rd3, %rd4};
+; CHECK-NEXT:    ret;
+  %1 = extractvalue [2 x i128] %a, 0
+  %2 = extractvalue [2 x i128] %a, 1
+  %3 = insertvalue [2 x i128] undef, i128 %1, 0
+  %4 = insertvalue [2 x i128] %3, i128 %2, 1
+
+  ret [2 x i128] %4
+}