[ARM][MVE] Tail-predication: predicate new elementcount checks on force-enabled

Sjoerd Meijer · Sjoerd Meijer · commit b5c3efeb7bc9 · 2020-09-16T17:05:14.000+01:00
Additional sanity checks were added to get.active.lane.mask's second argument, the loop tripcount/elementcount, in rG635b87511ec3. Like the other (overflow) checks, skip this if tail-predication is forced. Differential Revision: https://reviews.llvm.org/D87769
diff --git a/llvm/lib/Target/ARM/MVETailPredication.cpp b/llvm/lib/Target/ARM/MVETailPredication.cpp
@@ -411,7 +411,7 @@ bool MVETailPredication::IsSafeActiveMask(IntrinsicInst *ActiveLaneMask,
                  << TC2 << " from get.active.lane.mask\n");
       return false;
     }
-  } else {
+  } else if (!ForceTailPredication) {
     // Smoke tests if the element count is a runtime value. I.e., this isn't
     // fully generic because that would require a full SCEV visitor here. It
     // would require extracting the variable from the elementcount SCEV

Original file line number	Diff line number	Diff line change
`@@ -411,7 +411,7 @@ bool MVETailPredication::IsSafeActiveMask(IntrinsicInst *ActiveLaneMask,`
`411`	`411`	`<< TC2 << " from get.active.lane.mask\n");`
`412`	`412`	`return false;`
`413`	`413`	`}`
`414`		`- } else {`
	`414`	`+ } else if (!ForceTailPredication) {`
`415`	`415`	`// Smoke tests if the element count is a runtime value. I.e., this isn't`
`416`	`416`	`// fully generic because that would require a full SCEV visitor here. It`
`417`	`417`	`// would require extracting the variable from the elementcount SCEV`