[clang][CodeGen] Use index type for inline asm ptrtoint

When the return type of an inline asm instruction needs to be
truncated to an integer type we need to use the index type
and not the size of the pointer type so as to not crash.

Author: veselypeta

clang/lib/CodeGen/CGStmt.cpp

@@ -2796,7 +2796,7 @@ EmitAsmStores(CodeGenFunction &CGF, const AsmStmt &S,
         Tmp = Builder.CreateIntToPtr(Tmp, TruncTy);
       } else if (Tmp->getType()->isPointerTy() && TruncTy->isIntegerTy()) {
         uint64_t TmpSize =
-            CGM.getDataLayout().getTypeSizeInBits(Tmp->getType());
+            CGM.getDataLayout().getIndexTypeSizeInBits(Tmp->getType());
         Tmp = Builder.CreatePtrToInt(
             Tmp, llvm::IntegerType::get(CTX, (unsigned)TmpSize));
         Tmp = Builder.CreateTrunc(Tmp, TruncTy);

clang/test/CodeGen/cheri/cheri-asm-ptrtoint.c

@@ -0,0 +1,24 @@
+// NOTE: Assertions have been autogenerated by utils/update_cc_test_checks.py UTC_ARGS: --version 2
+// RUN: %riscv32_cheri_purecap_cc1 -disable-O0-optnone %s -emit-llvm -o - | opt -passes=mem2reg -S -o - | FileCheck %s --check-prefix=RV32
+// RUN: %riscv64_cheri_purecap_cc1 -disable-O0-optnone %s -emit-llvm -o - | opt -passes=mem2reg -S -o - | FileCheck %s --check-prefix=RV64
+
+// RV32-LABEL: define dso_local i32 @ptr_to_int
+// RV32-SAME: (ptr addrspace(200) noundef [[P:%.*]]) addrspace(200) #[[ATTR0:[0-9]+]] {
+// RV32-NEXT:  entry:
+// RV32-NEXT:    [[TMP0:%.*]] = call ptr addrspace(200) asm "", "=C,0"(ptr addrspace(200) [[P]]) #[[ATTR1:[0-9]+]], !srcloc [[META6:![0-9]+]]
+// RV32-NEXT:    [[TMP1:%.*]] = ptrtoint ptr addrspace(200) [[TMP0]] to i32
+// RV32-NEXT:    ret i32 [[TMP1]]
+//
+// RV64-LABEL: define dso_local signext i32 @ptr_to_int
+// RV64-SAME: (ptr addrspace(200) noundef [[P:%.*]]) addrspace(200) #[[ATTR0:[0-9]+]] {
+// RV64-NEXT:  entry:
+// RV64-NEXT:    [[TMP0:%.*]] = call ptr addrspace(200) asm "", "=C,0"(ptr addrspace(200) [[P]]) #[[ATTR1:[0-9]+]], !srcloc [[META6:![0-9]+]]
+// RV64-NEXT:    [[TMP1:%.*]] = ptrtoint ptr addrspace(200) [[TMP0]] to i64
+// RV64-NEXT:    [[TMP2:%.*]] = trunc i64 [[TMP1]] to i32
+// RV64-NEXT:    ret i32 [[TMP2]]
+//
+int ptr_to_int(void *p) {
+  int i;
+  asm ("" : "=C"(i) : "0"(p));
+  return i;
+}