[PATCH] D31609: [SystemZ] Fix bitcast of load translation to preserve alignment.

[Nirav Dave via Phabricator via llvm-commits]

niravd updated this revision to Diff 94231.
niravd added a comment.

update to prevent extended / indexed loads from being merged with bitcast.


https://reviews.llvm.org/D31609

Files:
  lib/Target/SystemZ/SystemZISelLowering.cpp
  test/CodeGen/SystemZ/pr32505.ll


Index: test/CodeGen/SystemZ/pr32505.ll
===================================================================
--- /dev/null
+++ test/CodeGen/SystemZ/pr32505.ll
@@ -0,0 +1,20 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
+; RUN: llc -mcpu=zEC12 -o - %s | FileCheck %s
+
+target triple = "s390x-ibm-linux"
+
+define <2 x float> @pr32505(<2 x i8> * %a) {
+; CHECK-LABEL: pr32505:
+; CHECK:       # BB#0:
+; CHECK-NEXT:    lbh %r0, 0(%r2)
+; CHECK-NEXT:    ldgr %f0, %r0
+; CHECK-NEXT:    lbh %r0, 1(%r2)
+; CHECK-NEXT:    ldgr %f2, %r0
+; CHECK-NEXT:    # kill: %F0S<def> %F0S<kill> %F0D<kill>
+; CHECK-NEXT:    # kill: %F2S<def> %F2S<kill> %F2D<kill>
+; CHECK-NEXT:    br %r14
+  %L17 = load <2 x i8>, <2 x i8>* %a
+  %Se21 = sext <2 x i8> %L17 to <2 x i32>
+  %BC = bitcast <2 x i32> %Se21 to <2 x float>
+  ret <2 x float> %BC
+}
Index: lib/Target/SystemZ/SystemZISelLowering.cpp
===================================================================
--- lib/Target/SystemZ/SystemZISelLowering.cpp
+++ lib/Target/SystemZ/SystemZISelLowering.cpp
@@ -2792,8 +2792,9 @@
   // but we need this case for bitcasts that are created during lowering
   // and which are then lowered themselves.
   if (auto *LoadN = dyn_cast<LoadSDNode>(In))
-    return DAG.getLoad(ResVT, DL, LoadN->getChain(), LoadN->getBasePtr(),
-                       LoadN->getMemOperand());
+    if (ISD::isNormalLoad(LoadN))
+      return DAG.getLoad(ResVT, DL, LoadN->getChain(), LoadN->getBasePtr(),
+                         LoadN->getMemOperand());
 
   if (InVT == MVT::i32 && ResVT == MVT::f32) {
     SDValue In64;


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