[llvm] cbd3068 - [APInt] Correct backwards static_assert condition. (#103641)

[via llvm-commits]

Author: Craig Topper
Date: 2024-08-14T00:28:24-07:00
New Revision: cbd306806ad4b518e664f122838e45d709db0ef6

URL: https://github.com/llvm/llvm-project/commit/cbd306806ad4b518e664f122838e45d709db0ef6
DIFF: https://github.com/llvm/llvm-project/commit/cbd306806ad4b518e664f122838e45d709db0ef6.diff

LOG: [APInt] Correct backwards static_assert condition. (#103641)

In order to guarantee that extracting 64 bits doesn't require more than
2 words, the word size would need to be 64 bits or more. If the word
size was smaller than 64, like 32, you may need to read 3 words to get
64 bits.

Added: 
    

Modified: 
    llvm/lib/Support/APInt.cpp

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Support/APInt.cpp b/llvm/lib/Support/APInt.cpp
index 87edf74e191d8..fe22e9ba04b6f 100644
--- a/llvm/lib/Support/APInt.cpp
+++ b/llvm/lib/Support/APInt.cpp
@@ -496,14 +496,14 @@ uint64_t APInt::extractBitsAsZExtValue(unsigned numBits,
   if (isSingleWord())
     return (U.VAL >> bitPosition) & maskBits;
 
+  static_assert(APINT_BITS_PER_WORD >= 64,
+                "This code assumes only two words affected");
   unsigned loBit = whichBit(bitPosition);
   unsigned loWord = whichWord(bitPosition);
   unsigned hiWord = whichWord(bitPosition + numBits - 1);
   if (loWord == hiWord)
     return (U.pVal[loWord] >> loBit) & maskBits;
 
-  static_assert(APINT_BITS_PER_WORD <= 64,
-                "This code assumes only two words affected");
   uint64_t retBits = U.pVal[loWord] >> loBit;
   retBits |= U.pVal[hiWord] << (APINT_BITS_PER_WORD - loBit);
   retBits &= maskBits;