[clang] [Clang][RISCV] Add missing support for `__builtin_riscv_cpop_32/64` (PR #76256)

[Craig Topper via cfe-commits]

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@@ -82,3 +82,29 @@ unsigned int ctz_64(unsigned long a) {
   return __builtin_riscv_ctz_64(a);
 }
 #endif
+
+// RV32ZBB-LABEL: @cpop_32(
+// RV32ZBB-NEXT:  entry:
+// RV32ZBB-NEXT:    [[TMP0:%.*]] = call i32 @llvm.ctpop.i32(i32 [[A:%.*]])
+// RV32ZBB-NEXT:    ret i32 [[TMP0]]
+//
+// RV64ZBB-LABEL: @cpop_32(
+// RV64ZBB-NEXT:  entry:
+// RV64ZBB-NEXT:    [[TMP0:%.*]] = call i32 @llvm.ctpop.i32(i32 [[A:%.*]])
+// RV64ZBB-NEXT:    ret i32 [[TMP0]]
+//
+unsigned int cpop_32(unsigned int a) {
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topperc wrote:

This should also be using the intrinsic from riscv_bitmanip.h

https://github.com/llvm/llvm-project/pull/76256