[Support] Simplify minIntN and isUIntN (NFC)

kazutakahirata · kazutakahirata · commit 81cd702718bf · 2025-11-04T22:35:01.000-08:00
diff --git a/llvm/include/llvm/Support/MathExtras.h b/llvm/include/llvm/Support/MathExtras.h
@@ -225,7 +225,7 @@ inline constexpr int64_t minIntN(int64_t N) {
 
   if (N == 0)
     return 0;
-  return UINT64_C(1) + ~(UINT64_C(1) << (N - 1));
+  return UINT64_MAX << (N - 1);
 }
 
 /// Gets the maximum value for a N-bit signed integer.
@@ -241,7 +241,7 @@ inline constexpr int64_t maxIntN(int64_t N) {
 
 /// Checks if an unsigned integer fits into the given (dynamic) bit width.
 inline constexpr bool isUIntN(unsigned N, uint64_t x) {
-  return N >= 64 || x <= maxUIntN(N);
+  return N >= 64 || (x >> N) == 0;
 }
 
 /// Checks if an signed integer fits into the given (dynamic) bit width.

Original file line number	Diff line number	Diff line change
`@@ -225,7 +225,7 @@ inline constexpr int64_t minIntN(int64_t N) {`
`225`	`225`
`226`	`226`	`if (N == 0)`
`227`	`227`	`return 0;`
`228`		`- return UINT64_C(1) + ~(UINT64_C(1) << (N - 1));`
	`228`	`+ return UINT64_MAX << (N - 1);`
`229`	`229`	`}`
`230`	`230`
`231`	`231`	`/// Gets the maximum value for a N-bit signed integer.`
`@@ -241,7 +241,7 @@ inline constexpr int64_t maxIntN(int64_t N) {`
`241`	`241`
`242`	`242`	`/// Checks if an unsigned integer fits into the given (dynamic) bit width.`
`243`	`243`	`inline constexpr bool isUIntN(unsigned N, uint64_t x) {`
`244`		`- return N >= 64 \|\| x <= maxUIntN(N);`
	`244`	`+ return N >= 64 \|\| (x >> N) == 0;`
`245`	`245`	`}`
`246`	`246`
`247`	`247`	`/// Checks if an signed integer fits into the given (dynamic) bit width.`