[llvm] Reland "DAG: Preserve range metadata when load is narrowed" (#128144) (PR #130609)

[Matt Arsenault via llvm-commits]

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@@ -0,0 +1,21 @@
+; RUN: llc < %s
+;
+; This test case is reduced from RangeConstraintManager.cpp in a ASan build.
+; It crashes reduceLoadWidth in DAGCombiner.cpp. Preservation of range
+; metdata must ensure that ConstantRange truncation is strictly smaller.
+
+target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-i128:128-f80:128-n8:16:32:64-S128"
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arsenm wrote:

Usually drop the datalayout and move the triple to the command line argument 

https://github.com/llvm/llvm-project/pull/130609