[clang] [llvm] [llvm:ir] Add support for constant data exceeding 4GiB (PR #126481)

[via llvm-commits]

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@@ -1583,7 +1583,7 @@ static void printConstant(const Constant *COp, unsigned BitWidth,
     bool IsInteger = EltTy->isIntegerTy();
     bool IsFP = EltTy->isHalfTy() || EltTy->isFloatTy() || EltTy->isDoubleTy();
     unsigned EltBits = EltTy->getPrimitiveSizeInBits();
-    unsigned E = std::min(BitWidth / EltBits, CDS->getNumElements());
+    unsigned E = std::min(BitWidth / EltBits, (unsigned)CDS->getNumElements());
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pzzp wrote:

Thank you very much for your meticulous review.
I update the test to this `gen_large_string.sh`
```bash
#!/bin/bash
cat << EOF
target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-i128:128-f80:128-n8:16:32:64-S128"
target triple = "x86_64-unknown-linux-gnu"
EOF

# generate @S = constant [4294967303 x i8] c"......", align 1
for (( i = 0; i<128; i++)); do
  S_1K+='abcdefgh'
done
for (( i = 0; i<1024; i++)); do
  S_1M+=$S_1K
done
echo -n "@S = constant [$((1024 * 1024 * 1024 * 4 + 7)) x i8] c\""
for (( i = 0; i<$((1024 * 4)); i++)); do
  echo -n $S_1M
done
echo -n 'last7ch'
echo '", align 1'

cat << EOF
!llvm.module.flags = !{!0, !1, !2, !3}

!0 = !{i32 1, !"wchar_size", i32 4}
!1 = !{i32 8, !"PIC Level", i32 2}
!2 = !{i32 7, !"PIE Level", i32 2}
!3 = !{i32 7, !"uwtable", i32 2}
EOF
```

```bash
bash gen_large_string.sh > a.ll
llc a.ll
```
It generate right result, with last 7 char are 'last7ch'.
![image](https://github.com/user-attachments/assets/1f41cb0d-2e72-4f07-a19e-c233827fef0d)
![image](https://github.com/user-attachments/assets/9b1aff74-6987-46ba-ae27-fa88ce926ebf)

 

https://github.com/llvm/llvm-project/pull/126481