[AMDGCN] Error checking for llvm.amdgcn.init.exec.from.input intrinsic

llvm/lib/Target/AMDGPU/SIWholeQuadMode.cpp

@@ -1622,7 +1622,21 @@ void SIWholeQuadMode::lowerInitExec(MachineInstr &MI) {
   MachineInstr *FirstMI = &*MBB->begin();
   if (InputReg.isVirtual()) {
     MachineInstr *DefInstr = MRI->getVRegDef(InputReg);
-    assert(DefInstr && DefInstr->isCopy());
+    // This condition catches some cases where a
+    // llvm.amdgcn.init.exec.from.input intrinsic's first argument comes from
+    // somewhere other than a (SGPR) function argument, which is forbidden.
+    if (!DefInstr || !DefInstr->isCopy() ||
+        (DefInstr->getNumOperands() == 2 && DefInstr->getOperand(1).isReg() &&
+         TRI->isVectorRegister(*MRI, DefInstr->getOperand(1).getReg()))) {
+      MachineFunction *MF = MBB->getParent();
+      DebugLoc DL = DefInstr->getDebugLoc();
+      DiagnosticInfoUnsupported IllegalArg(
+          MF->getFunction(), "EXEC must be initialized using function argument",
+          DL, DS_Error);
+      LLVMContext &C = MF->getFunction().getContext();
+      C.diagnose(IllegalArg);
+      return;
+    }
     if (DefInstr->getParent() == MBB) {
       if (DefInstr != FirstMI) {
         // If the `InputReg` is defined in current block, we also need to

llvm/test/CodeGen/AMDGPU/GlobalISel/regbankselect-intrinsic-initexecfrominput.ll

@@ -0,0 +1,40 @@
+; RUN: not llc -mtriple=amdgcn -mcpu=gfx942 -O3 -global-isel=true -o - %s 2>&1 | FileCheck -check-prefix=ERR %s
+
+source_filename = "llvm.amdgcn.init.exec.wave32.ll"
+
+@G = global i32 -2147483648
+@G.1 = global <32 x i32> splat (i32 1)
+@G.2 = global <16 x i64> splat (i64 1)
+@G.3 = global <8 x i1> zeroinitializer
+
+define amdgpu_ps float @test_init_exec(float %a, float %b) {
+main_body:
+  %s = fadd float %a, %b
+  call void @llvm.amdgcn.init.exec(i64 74565)
+  ret float %s
+}
+
+define amdgpu_ps float @test_init_exec_from_input(i32 inreg %0, i32 inreg %1, i32 inreg %2, i32 inreg %count, float %a, float %b) {
+main_body:
+  %LGV2 = load <16 x i64>, ptr @G.2, align 128
+  %LGV1 = load <32 x i32>, ptr @G.1, align 128
+  %LGV = load i32, ptr @G, align 4
+  %C = call <8 x i1> @f(<32 x i32> %LGV1, <16 x i64> %LGV2, <2 x half> splat (half 0xH5140))
+  %B = or i32 0, %LGV
+  %s = fadd float %a, %b
+  call void @llvm.amdgcn.init.exec.from.input(i32 %B, i32 8)
+  store <8 x i1> %C, ptr @G.3, align 1
+  ret float %s
+}
+
+; Function Attrs: convergent nocallback nofree nounwind willreturn
+declare void @llvm.amdgcn.init.exec(i64 immarg) #0
+
+; Function Attrs: convergent nocallback nofree nounwind willreturn
+declare void @llvm.amdgcn.init.exec.from.input(i32, i32 immarg) #0
+
+declare <8 x i1> @f(<32 x i32>, <16 x i64>, <2 x half>)
+
+attributes #0 = { convergent nocallback nofree nounwind willreturn }
+
+ERR: error: <unknown>:0:0: in function test_init_exec_from_input float (i32, i32, i32, i32, float, float): EXEC must be initialized using function argument

llvm/test/CodeGen/AMDGPU/intrinsic-initexecfrominput.ll

@@ -0,0 +1,40 @@
+; RUN: not llc -mtriple=amdgcn -mcpu=gfx942 -O3 -global-isel=false -o - %s 2>&1 | FileCheck -check-prefix=ERR %s
+
+source_filename = "llvm.amdgcn.init.exec.wave32.ll"
+
+@G = global i32 -2147483648
+@G.1 = global <32 x i32> splat (i32 1)
+@G.2 = global <16 x i64> splat (i64 1)
+@G.3 = global <8 x i1> zeroinitializer
+
+define amdgpu_ps float @test_init_exec(float %a, float %b) {
+main_body:
+  %s = fadd float %a, %b
+  call void @llvm.amdgcn.init.exec(i64 74565)
+  ret float %s
+}
+
+define amdgpu_ps float @test_init_exec_from_input(i32 inreg %0, i32 inreg %1, i32 inreg %2, i32 inreg %count, float %a, float %b) {
+main_body:
+  %LGV2 = load <16 x i64>, ptr @G.2, align 128
+  %LGV1 = load <32 x i32>, ptr @G.1, align 128
+  %LGV = load i32, ptr @G, align 4
+  %C = call <8 x i1> @f(<32 x i32> %LGV1, <16 x i64> %LGV2, <2 x half> splat (half 0xH5140))
+  %B = or i32 0, %LGV
+  %s = fadd float %a, %b
+  call void @llvm.amdgcn.init.exec.from.input(i32 %B, i32 8)
+  store <8 x i1> %C, ptr @G.3, align 1
+  ret float %s
+}
+
+; Function Attrs: convergent nocallback nofree nounwind willreturn
+declare void @llvm.amdgcn.init.exec(i64 immarg) #0
+
+; Function Attrs: convergent nocallback nofree nounwind willreturn
+declare void @llvm.amdgcn.init.exec.from.input(i32, i32 immarg) #0
+
+declare <8 x i1> @f(<32 x i32>, <16 x i64>, <2 x half>)
+
+attributes #0 = { convergent nocallback nofree nounwind willreturn }
+
+ERR: error: <unknown>:0:0: in function test_init_exec_from_input float (i32, i32, i32, i32, float, float): EXEC must be initialized using function argument