[llvm-branch-commits] [llvm] ade175b - Revert "[DAGCombiner] Fold pattern for srl-shl-zext (#138290)"
via llvm-branch-commits
llvm-branch-commits at lists.llvm.org
Wed May 14 04:12:22 PDT 2025
Author: Simon Pilgrim
Date: 2025-05-14T12:12:20+01:00
New Revision: ade175b3e65bb0d051f8c4e389e32dc3eb12d164
URL: https://github.com/llvm/llvm-project/commit/ade175b3e65bb0d051f8c4e389e32dc3eb12d164
DIFF: https://github.com/llvm/llvm-project/commit/ade175b3e65bb0d051f8c4e389e32dc3eb12d164.diff
LOG: Revert "[DAGCombiner] Fold pattern for srl-shl-zext (#138290)"
This reverts commit bbc5221c95343d8d6869dce83d6fcf183767bd9f.
Added:
Modified:
llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
Removed:
llvm/test/CodeGen/NVPTX/shift-opt.ll
################################################################################
diff --git a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
index 8671efcfd2fb1..d6e288a59b2ee 100644
--- a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -10972,22 +10972,6 @@ SDValue DAGCombiner::visitSRL(SDNode *N) {
return DAG.getNode(ISD::SRL, DL, VT, N0, NewOp1);
}
- // fold (srl (logic_op x, (shl (zext y), c1)), c1)
- // -> (logic_op (srl x, c1), (zext y))
- // c1 <= leadingzeros(zext(y))
- SDValue X, ZExtY;
- if (N1C && sd_match(N0, m_OneUse(m_BitwiseLogic(
- m_Value(X),
- m_OneUse(m_Shl(m_AllOf(m_Value(ZExtY),
- m_Opc(ISD::ZERO_EXTEND)),
- m_Specific(N1))))))) {
- unsigned NumLeadingZeros = ZExtY.getScalarValueSizeInBits() -
- ZExtY.getOperand(0).getScalarValueSizeInBits();
- if (N1C->getZExtValue() <= NumLeadingZeros)
- return DAG.getNode(N0.getOpcode(), SDLoc(N0), VT,
- DAG.getNode(ISD::SRL, SDLoc(N0), VT, X, N1), ZExtY);
- }
-
// fold operands of srl based on knowledge that the low bits are not
// demanded.
if (SimplifyDemandedBits(SDValue(N, 0)))
diff --git a/llvm/test/CodeGen/NVPTX/shift-opt.ll b/llvm/test/CodeGen/NVPTX/shift-opt.ll
deleted file mode 100644
index 010ea7ad5c844..0000000000000
--- a/llvm/test/CodeGen/NVPTX/shift-opt.ll
+++ /dev/null
@@ -1,152 +0,0 @@
-; RUN: llc < %s -mtriple=nvptx64 | FileCheck %s
-
-define i64 @test_or(i64 %x, i32 %y) {
-;
-; Fold: srl (or (x, shl(zext(y),c1)),c1) -> or(srl(x,c1), zext(y))
-; c1 <= leadingzeros(zext(y))
-;
-; CHECK-LABEL: test_or
-; CHECK: ld.param.u64 %[[X:rd[0-9]+]], [test_or_param_0];
-; CHECK: ld.param.u32 %[[Y:rd[0-9]+]], [test_or_param_1];
-; CHECK: shr.u64 %[[SHR:rd[0-9]+]], %[[X]], 5;
-; CHECK: or.b64 %[[LOP:rd[0-9]+]], %[[SHR]], %[[Y]];
-; CHECK: st.param.b64 [func_retval0], %[[LOP]];
-;
- %ext = zext i32 %y to i64
- %shl = shl i64 %ext, 5
- %or = or i64 %x, %shl
- %srl = lshr i64 %or, 5
- ret i64 %srl
-}
-
-define i64 @test_xor(i64 %x, i32 %y) {
-;
-; Fold: srl (xor (x, shl(zext(y),c1)),c1) -> xor(srl(x,c1), zext(y))
-; c1 <= leadingzeros(zext(y))
-;
-; CHECK-LABEL: test_xor
-; CHECK: ld.param.u64 %[[X:rd[0-9]+]], [test_xor_param_0];
-; CHECK: ld.param.u32 %[[Y:rd[0-9]+]], [test_xor_param_1];
-; CHECK: shr.u64 %[[SHR:rd[0-9]+]], %[[X]], 5;
-; CHECK: xor.b64 %[[LOP:rd[0-9]+]], %[[SHR]], %[[Y]];
-; CHECK: st.param.b64 [func_retval0], %[[LOP]];
-;
- %ext = zext i32 %y to i64
- %shl = shl i64 %ext, 5
- %or = xor i64 %x, %shl
- %srl = lshr i64 %or, 5
- ret i64 %srl
-}
-
-define i64 @test_and(i64 %x, i32 %y) {
-;
-; Fold: srl (and (x, shl(zext(y),c1)),c1) -> and(srl(x,c1), zext(y))
-; c1 <= leadingzeros(zext(y))
-;
-; CHECK-LABEL: test_and
-; CHECK: ld.param.u64 %[[X:rd[0-9]+]], [test_and_param_0];
-; CHECK: ld.param.u32 %[[Y:rd[0-9]+]], [test_and_param_1];
-; CHECK: shr.u64 %[[SHR:rd[0-9]+]], %[[X]], 5;
-; CHECK: and.b64 %[[LOP:rd[0-9]+]], %[[SHR]], %[[Y]];
-; CHECK: st.param.b64 [func_retval0], %[[LOP]];
-;
- %ext = zext i32 %y to i64
- %shl = shl i64 %ext, 5
- %or = and i64 %x, %shl
- %srl = lshr i64 %or, 5
- ret i64 %srl
-}
-
-define <2 x i16> @test_vec(<2 x i16> %x, <2 x i8> %y) {
-;
-; Fold: srl (or (x, shl(zext(y),c1)),c1) -> or(srl(x,c1), zext(y))
-; c1 <= leadingzeros(zext(y))
-; x, y - vectors
-;
-; CHECK-LABEL: test_vec
-; CHECK: ld.param.u32 %[[X:r[0-9]+]], [test_vec_param_0];
-; CHECK: ld.param.u32 %[[P1:r[0-9]+]], [test_vec_param_1];
-; CHECK: and.b32 %[[Y:r[0-9]+]], %[[P1]], 16711935;
-; CHECK: mov.b32 {%[[X1:rs[0-9]+]], %[[X2:rs[0-9]+]]}, %[[X]];
-; CHECK: shr.u16 %[[SHR2:rs[0-9]+]], %[[X2]], 5;
-; CHECK: shr.u16 %[[SHR1:rs[0-9]+]], %[[X1]], 5;
-; CHECK: mov.b32 %[[SHR:r[0-9]+]], {%[[SHR1]], %[[SHR2]]};
-; CHECK: or.b32 %[[LOP:r[0-9]+]], %[[SHR]], %[[Y]];
-; CHECK: st.param.b32 [func_retval0], %[[LOP]];
-;
- %ext = zext <2 x i8> %y to <2 x i16>
- %shl = shl <2 x i16> %ext, splat(i16 5)
- %or = or <2 x i16> %x, %shl
- %srl = lshr <2 x i16> %or, splat(i16 5)
- ret <2 x i16> %srl
-}
-
-define i64 @test_negative_c(i64 %x, i32 %y) {
-;
-; Do not fold: srl (or (x, shl(zext(y),c1)),c1) -> or(srl(x,c1), zext(y))
-; Reason: c1 > leadingzeros(zext(y)).
-;
-; CHECK-LABEL: test_negative_c
-; CHECK: ld.param.u64 %[[X:rd[0-9]+]], [test_negative_c_param_0];
-; CHECK: ld.param.u32 %[[Y:rd[0-9]+]], [test_negative_c_param_1];
-; CHECK: shl.b64 %[[SHL:rd[0-9]+]], %[[Y]], 33;
-; CHECK: or.b64 %[[OR:rd[0-9]+]], %[[X]], %[[SHL]];
-; CHECK: shr.u64 %[[SHR:rd[0-9]+]], %[[OR]], 33;
-; CHECK: st.param.b64 [func_retval0], %[[SHR]];
-;
- %ext = zext i32 %y to i64
- %shl = shl i64 %ext, 33
- %or = or i64 %x, %shl
- %srl = lshr i64 %or, 33
- ret i64 %srl
-}
-
-declare void @use(i64)
-
-define i64 @test_negative_use_lop(i64 %x, i32 %y) {
-;
-; Do not fold: srl (or (x, shl(zext(y),c1)),c1) -> or(srl(x,c1), zext(y))
-; Reason: multiple usage of "or"
-;
-; CHECK-LABEL: test_negative_use_lop
-; CHECK: ld.param.u64 %[[X:rd[0-9]+]], [test_negative_use_lop_param_0];
-; CHECK: ld.param.u32 %[[Y:r[0-9]+]], [test_negative_use_lop_param_1];
-; CHECK: mul.wide.u32 %[[SHL:rd[0-9]+]], %[[Y]], 32;
-; CHECK: or.b64 %[[OR:rd[0-9]+]], %[[X]], %[[SHL]];
-; CHECK: shr.u64 %[[SHR:rd[0-9]+]], %[[OR]], 5;
-; CHECK: { // callseq
-; CHECK: st.param.b64 [param0], %[[OR]];
-; CHECK: } // callseq
-; CHECK: st.param.b64 [func_retval0], %[[SHR]];
-;
- %ext = zext i32 %y to i64
- %shl = shl i64 %ext, 5
- %or = or i64 %x, %shl
- %srl = lshr i64 %or, 5
- call void @use(i64 %or)
- ret i64 %srl
-}
-
-define i64 @test_negative_use_shl(i64 %x, i32 %y) {
-;
-; Do not fold: srl (or (x, shl(zext(y),c1)),c1) -> or(srl(x,c1), zext(y))
-; Reason: multiple usage of "shl"
-;
-; CHECK-LABEL: test_negative_use_shl
-; CHECK: ld.param.u64 %[[X:rd[0-9]+]], [test_negative_use_shl_param_0];
-; CHECK: ld.param.u32 %[[Y:r[0-9]+]], [test_negative_use_shl_param_1];
-; CHECK: mul.wide.u32 %[[SHL:rd[0-9]+]], %[[Y]], 32;
-; CHECK: or.b64 %[[OR:rd[0-9]+]], %[[X]], %[[SHL]];
-; CHECK: shr.u64 %[[SHR:rd[0-9]+]], %[[OR]], 5;
-; CHECK: { // callseq
-; CHECK: st.param.b64 [param0], %[[SHL]];
-; CHECK: } // callseq
-; CHECK: st.param.b64 [func_retval0], %[[SHR]];
-;
- %ext = zext i32 %y to i64
- %shl = shl i64 %ext, 5
- %or = or i64 %x, %shl
- %srl = lshr i64 %or, 5
- call void @use(i64 %shl)
- ret i64 %srl
-}
More information about the llvm-branch-commits
mailing list