[llvm] [LV] Use SCEV to check if minimum iteration check is known. (PR #111310)

[via llvm-commits]

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@@ -791,10 +768,7 @@ for.cond.cleanup:
 define double @test_widen_fmuladd_and_call(ptr noalias %a, ptr readnone %b, double %m) #4 {
 ; TFNONE-LABEL: @test_widen_fmuladd_and_call(
 ; TFNONE-NEXT:  entry:
-; TFNONE-NEXT:    [[TMP0:%.*]] = call i64 @llvm.vscale.i64()
-; TFNONE-NEXT:    [[TMP1:%.*]] = mul i64 [[TMP0]], 2
-; TFNONE-NEXT:    [[MIN_ITERS_CHECK:%.*]] = icmp ult i64 1025, [[TMP1]]
-; TFNONE-NEXT:    br i1 [[MIN_ITERS_CHECK]], label [[SCALAR_PH:%.*]], label [[VECTOR_PH:%.*]]
+; TFNONE-NEXT:    br i1 false, label [[SCALAR_PH:%.*]], label [[VECTOR_PH:%.*]]
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ayalz wrote:

ditto with vscale_range(2,16)

https://github.com/llvm/llvm-project/pull/111310