[PATCH] D20175: [AArch64] Improve getUsefulBitsForUse for narrow stores.
Chad Rosier via llvm-commits
llvm-commits at lists.llvm.org
Wed May 11 12:41:34 PDT 2016
mcrosier updated this revision to Diff 56951.
mcrosier added a comment.
Address Geoff's comments:
-Update description
-Make sure the use is the stores first source operand (i.e., the value being stored).
http://reviews.llvm.org/D20175
Files:
lib/Target/AArch64/AArch64ISelDAGToDAG.cpp
test/CodeGen/AArch64/bitfield-insert.ll
Index: test/CodeGen/AArch64/bitfield-insert.ll
===================================================================
--- test/CodeGen/AArch64/bitfield-insert.ll
+++ test/CodeGen/AArch64/bitfield-insert.ll
@@ -237,3 +237,39 @@
%shl.4 = shl i32 %or.3, 8 ; A A A 0
ret i32 %shl.4
}
+
+define void @test_nouseful_strb(i32* %ptr32, i8* %ptr8, i32 %x) {
+entry:
+; CHECK-LABEL: @test_nouseful_strb
+; CHECK: ldr [[REG1:w[0-9]+]],
+; CHECK-NOT: and {{w[0-9]+}}, {{w[0-9]+}}, #0xf8
+; CHECK-NEXT: bfxil [[REG1]], w2, #16, #3
+; CHECK-NEXT: strb [[REG1]],
+; CHECK-NEXT: ret
+ %0 = load i32, i32* %ptr32, align 8
+ %and = and i32 %0, -8
+ %shr = lshr i32 %x, 16
+ %and1 = and i32 %shr, 7
+ %or = or i32 %and, %and1
+ %trunc = trunc i32 %or to i8
+ store i8 %trunc, i8* %ptr8
+ ret void
+}
+
+define void @test_nouseful_strh(i32* %ptr32, i16* %ptr16, i32 %x) {
+entry:
+; CHECK-LABEL: @test_nouseful_strh
+; CHECK: ldr [[REG1:w[0-9]+]],
+; CHECK-NOT: and {{w[0-9]+}}, {{w[0-9]+}}, #0xfff0
+; CHECK-NEXT: bfxil [[REG1]], w2, #16, #4
+; CHECK-NEXT: strh [[REG1]],
+; CHECK-NEXT: ret
+ %0 = load i32, i32* %ptr32, align 8
+ %and = and i32 %0, -16
+ %shr = lshr i32 %x, 16
+ %and1 = and i32 %shr, 15
+ %or = or i32 %and, %and1
+ %trunc = trunc i32 %or to i16
+ store i16 %trunc, i16* %ptr16
+ ret void
+}
Index: lib/Target/AArch64/AArch64ISelDAGToDAG.cpp
===================================================================
--- lib/Target/AArch64/AArch64ISelDAGToDAG.cpp
+++ lib/Target/AArch64/AArch64ISelDAGToDAG.cpp
@@ -1849,6 +1849,21 @@
case AArch64::BFMWri:
case AArch64::BFMXri:
return getUsefulBitsFromBFM(SDValue(UserNode, 0), Orig, UsefulBits, Depth);
+
+ case AArch64::STRBui:
+ case AArch64::STRBBui:
+ if (UserNode->getOperand(0) != Orig)
+ return;
+ UserNode->dump();
+ UsefulBits &= APInt(UsefulBits.getBitWidth(), 0xff);
+ return;
+
+ case AArch64::STRHui:
+ case AArch64::STRHHui:
+ if (UserNode->getOperand(0) != Orig)
+ return;
+ UsefulBits &= APInt(UsefulBits.getBitWidth(), 0xffff);
+ return;
}
}
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