================
@@ -2621,9 +2621,18 @@ EmitAsmStores(CodeGenFunction &CGF, const AsmStmt &S,
if ((i < ResultRegIsFlagReg.size()) && ResultRegIsFlagReg[i]) {
// Target must guarantee the Value `Tmp` here is lowered to a boolean
// value.
- llvm::Constant *Two = llvm::ConstantInt::get(Tmp->getType(), 2);
+ // Lowering 'Tmp' as - 'icmp ult %Tmp , CCUpperBound'. On some targets
+ // CCUpperBound is not binary. CCUpperBound is 4 for SystemZ,
+ // interval [0, 4). With this range known, llvm.assume intrinsic guides
+ // optimizer to generate more optimized IR in most of the cases as
+ // observed for select_cc on SystemZ unit tests for flag output operands.
+ // For some cases for br_cc, generated IR was weird. e.g. switch table
+ // for simple simple comparison terms for br_cc.
----------------
uweigand wrote:
You don't need to explain that wrong code will result from an incorrect
assertion.
https://github.com/llvm/llvm-project/pull/125970
_______________________________________________
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
