[llvm] [RISCV][SelectionDAG] Sign extend splats of i32 in getConstant on RV64 (PR #67027)

via llvm-commits llvm-commits at lists.llvm.org
Thu Sep 21 08:06:53 PDT 2023


llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-llvm-selectiondag

<details>
<summary>Changes</summary>

We get better constant materialization if we sign extend the value to be
splatted for i32 on RV64 instead of zero extending it.


---
Full diff: https://github.com/llvm/llvm-project/pull/67027.diff


5 Files Affected:

- (modified) llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp (+5-1) 
- (modified) llvm/test/CodeGen/RISCV/rvv/constant-folding.ll (+12-20) 
- (modified) llvm/test/CodeGen/RISCV/rvv/sshl_sat_vec.ll (+4-8) 
- (modified) llvm/test/CodeGen/RISCV/rvv/vmulh-sdnode.ll (+27-60) 
- (modified) llvm/test/CodeGen/RISCV/rvv/vmulhu-sdnode.ll (+24-60) 


``````````diff
diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
index f12db53c7f08738..cc162eb6dbca62c 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -1620,7 +1620,11 @@ SDValue SelectionDAG::getConstant(const ConstantInt &Val, const SDLoc &DL,
   if (VT.isVector() && TLI->getTypeAction(*getContext(), EltVT) ==
                            TargetLowering::TypePromoteInteger) {
     EltVT = TLI->getTypeToTransformTo(*getContext(), EltVT);
-    APInt NewVal = Elt->getValue().zextOrTrunc(EltVT.getSizeInBits());
+    APInt NewVal;
+    if (TLI->isSExtCheaperThanZExt(VT.getScalarType(), EltVT))
+      NewVal = Elt->getValue().sextOrTrunc(EltVT.getSizeInBits());
+    else
+      NewVal = Elt->getValue().zextOrTrunc(EltVT.getSizeInBits());
     Elt = ConstantInt::get(*getContext(), NewVal);
   }
   // In other cases the element type is illegal and needs to be expanded, for
diff --git a/llvm/test/CodeGen/RISCV/rvv/constant-folding.ll b/llvm/test/CodeGen/RISCV/rvv/constant-folding.ll
index e3a878052ee19b6..98bc4081b3a34e7 100644
--- a/llvm/test/CodeGen/RISCV/rvv/constant-folding.ll
+++ b/llvm/test/CodeGen/RISCV/rvv/constant-folding.ll
@@ -14,26 +14,15 @@
 ; a constant SPLAT_VECTOR didn't follow suit.
 
 define <2 x i16> @fixedlen(<2 x i32> %x) {
-; RV32-LABEL: fixedlen:
-; RV32:       # %bb.0:
-; RV32-NEXT:    vsetivli zero, 2, e32, mf2, ta, ma
-; RV32-NEXT:    vsrl.vi v8, v8, 16
-; RV32-NEXT:    lui a0, 1048568
-; RV32-NEXT:    vand.vx v8, v8, a0
-; RV32-NEXT:    vsetvli zero, zero, e16, mf4, ta, ma
-; RV32-NEXT:    vnsrl.wi v8, v8, 0
-; RV32-NEXT:    ret
-;
-; RV64-LABEL: fixedlen:
-; RV64:       # %bb.0:
-; RV64-NEXT:    vsetivli zero, 2, e32, mf2, ta, ma
-; RV64-NEXT:    vsrl.vi v8, v8, 16
-; RV64-NEXT:    lui a0, 131071
-; RV64-NEXT:    slli a0, a0, 3
-; RV64-NEXT:    vand.vx v8, v8, a0
-; RV64-NEXT:    vsetvli zero, zero, e16, mf4, ta, ma
-; RV64-NEXT:    vnsrl.wi v8, v8, 0
-; RV64-NEXT:    ret
+; CHECK-LABEL: fixedlen:
+; CHECK:       # %bb.0:
+; CHECK-NEXT:    vsetivli zero, 2, e32, mf2, ta, ma
+; CHECK-NEXT:    vsrl.vi v8, v8, 16
+; CHECK-NEXT:    lui a0, 1048568
+; CHECK-NEXT:    vand.vx v8, v8, a0
+; CHECK-NEXT:    vsetvli zero, zero, e16, mf4, ta, ma
+; CHECK-NEXT:    vnsrl.wi v8, v8, 0
+; CHECK-NEXT:    ret
   %v41 = insertelement <2 x i32> poison, i32 16, i32 0
   %v42 = shufflevector <2 x i32> %v41, <2 x i32> poison, <2 x i32> zeroinitializer
   %v43 = lshr <2 x i32> %x, %v42
@@ -63,3 +52,6 @@ define <vscale x 2 x i16> @scalable(<vscale x 2 x i32> %x) {
   %v48 = and <vscale x 2 x i16> %v44, %v47
   ret <vscale x 2 x i16> %v48
 }
+;; NOTE: These prefixes are unused and the list is autogenerated. Do not add tests below this line:
+; RV32: {{.*}}
+; RV64: {{.*}}
diff --git a/llvm/test/CodeGen/RISCV/rvv/sshl_sat_vec.ll b/llvm/test/CodeGen/RISCV/rvv/sshl_sat_vec.ll
index 443fe93a618c50b..56d98981947c3c0 100644
--- a/llvm/test/CodeGen/RISCV/rvv/sshl_sat_vec.ll
+++ b/llvm/test/CodeGen/RISCV/rvv/sshl_sat_vec.ll
@@ -32,13 +32,11 @@ define <4 x i32> @vec_v4i32(<4 x i32> %x, <4 x i32> %y) nounwind {
 ; CHECK-NEXT:    vsetivli zero, 4, e32, m1, ta, ma
 ; CHECK-NEXT:    vmsle.vi v0, v8, -1
 ; CHECK-NEXT:    lui a0, 524288
-; CHECK-NEXT:    addiw a0, a0, -1
+; CHECK-NEXT:    addiw a1, a0, -1
 ; CHECK-NEXT:    vsll.vv v10, v8, v9
 ; CHECK-NEXT:    vsra.vv v9, v10, v9
 ; CHECK-NEXT:    vmsne.vv v8, v8, v9
-; CHECK-NEXT:    vmv.v.x v9, a0
-; CHECK-NEXT:    li a0, 1
-; CHECK-NEXT:    slli a0, a0, 31
+; CHECK-NEXT:    vmv.v.x v9, a1
 ; CHECK-NEXT:    vmerge.vxm v9, v9, a0, v0
 ; CHECK-NEXT:    vmv.v.v v0, v8
 ; CHECK-NEXT:    vmerge.vvm v8, v10, v9, v0
@@ -116,13 +114,11 @@ define <vscale x 4 x i32> @vec_nxv4i32(<vscale x 4 x i32> %x, <vscale x 4 x i32>
 ; CHECK-NEXT:    vsetvli a0, zero, e32, m2, ta, ma
 ; CHECK-NEXT:    vmsle.vi v0, v8, -1
 ; CHECK-NEXT:    lui a0, 524288
-; CHECK-NEXT:    addiw a0, a0, -1
+; CHECK-NEXT:    addiw a1, a0, -1
 ; CHECK-NEXT:    vsll.vv v12, v8, v10
 ; CHECK-NEXT:    vsra.vv v14, v12, v10
 ; CHECK-NEXT:    vmsne.vv v10, v8, v14
-; CHECK-NEXT:    vmv.v.x v8, a0
-; CHECK-NEXT:    li a0, 1
-; CHECK-NEXT:    slli a0, a0, 31
+; CHECK-NEXT:    vmv.v.x v8, a1
 ; CHECK-NEXT:    vmerge.vxm v8, v8, a0, v0
 ; CHECK-NEXT:    vmv1r.v v0, v10
 ; CHECK-NEXT:    vmerge.vvm v8, v12, v8, v0
diff --git a/llvm/test/CodeGen/RISCV/rvv/vmulh-sdnode.ll b/llvm/test/CodeGen/RISCV/rvv/vmulh-sdnode.ll
index 06f5d39622da834..69191ebb9256d79 100644
--- a/llvm/test/CodeGen/RISCV/rvv/vmulh-sdnode.ll
+++ b/llvm/test/CodeGen/RISCV/rvv/vmulh-sdnode.ll
@@ -60,21 +60,12 @@ define <vscale x 1 x i32> @vmulh_vx_nxv1i32(<vscale x 1 x i32> %va, i32 %x) {
 }
 
 define <vscale x 1 x i32> @vmulh_vi_nxv1i32_0(<vscale x 1 x i32> %va) {
-; RV32-LABEL: vmulh_vi_nxv1i32_0:
-; RV32:       # %bb.0:
-; RV32-NEXT:    li a0, -7
-; RV32-NEXT:    vsetvli a1, zero, e32, mf2, ta, ma
-; RV32-NEXT:    vmulh.vx v8, v8, a0
-; RV32-NEXT:    ret
-;
-; RV64-LABEL: vmulh_vi_nxv1i32_0:
-; RV64:       # %bb.0:
-; RV64-NEXT:    li a0, 1
-; RV64-NEXT:    slli a0, a0, 32
-; RV64-NEXT:    addi a0, a0, -7
-; RV64-NEXT:    vsetvli a1, zero, e32, mf2, ta, ma
-; RV64-NEXT:    vmulh.vx v8, v8, a0
-; RV64-NEXT:    ret
+; CHECK-LABEL: vmulh_vi_nxv1i32_0:
+; CHECK:       # %bb.0:
+; CHECK-NEXT:    li a0, -7
+; CHECK-NEXT:    vsetvli a1, zero, e32, mf2, ta, ma
+; CHECK-NEXT:    vmulh.vx v8, v8, a0
+; CHECK-NEXT:    ret
   %head1 = insertelement <vscale x 1 x i32> poison, i32 -7, i32 0
   %splat1 = shufflevector <vscale x 1 x i32> %head1, <vscale x 1 x i32> poison, <vscale x 1 x i32> zeroinitializer
   %vb = sext <vscale x 1 x i32> %splat1 to <vscale x 1 x i64>
@@ -141,21 +132,12 @@ define <vscale x 2 x i32> @vmulh_vx_nxv2i32(<vscale x 2 x i32> %va, i32 %x) {
 }
 
 define <vscale x 2 x i32> @vmulh_vi_nxv2i32_0(<vscale x 2 x i32> %va) {
-; RV32-LABEL: vmulh_vi_nxv2i32_0:
-; RV32:       # %bb.0:
-; RV32-NEXT:    li a0, -7
-; RV32-NEXT:    vsetvli a1, zero, e32, m1, ta, ma
-; RV32-NEXT:    vmulh.vx v8, v8, a0
-; RV32-NEXT:    ret
-;
-; RV64-LABEL: vmulh_vi_nxv2i32_0:
-; RV64:       # %bb.0:
-; RV64-NEXT:    li a0, 1
-; RV64-NEXT:    slli a0, a0, 32
-; RV64-NEXT:    addi a0, a0, -7
-; RV64-NEXT:    vsetvli a1, zero, e32, m1, ta, ma
-; RV64-NEXT:    vmulh.vx v8, v8, a0
-; RV64-NEXT:    ret
+; CHECK-LABEL: vmulh_vi_nxv2i32_0:
+; CHECK:       # %bb.0:
+; CHECK-NEXT:    li a0, -7
+; CHECK-NEXT:    vsetvli a1, zero, e32, m1, ta, ma
+; CHECK-NEXT:    vmulh.vx v8, v8, a0
+; CHECK-NEXT:    ret
   %head1 = insertelement <vscale x 2 x i32> poison, i32 -7, i32 0
   %splat1 = shufflevector <vscale x 2 x i32> %head1, <vscale x 2 x i32> poison, <vscale x 2 x i32> zeroinitializer
   %vb = sext <vscale x 2 x i32> %splat1 to <vscale x 2 x i64>
@@ -222,21 +204,12 @@ define <vscale x 4 x i32> @vmulh_vx_nxv4i32(<vscale x 4 x i32> %va, i32 %x) {
 }
 
 define <vscale x 4 x i32> @vmulh_vi_nxv4i32_0(<vscale x 4 x i32> %va) {
-; RV32-LABEL: vmulh_vi_nxv4i32_0:
-; RV32:       # %bb.0:
-; RV32-NEXT:    li a0, -7
-; RV32-NEXT:    vsetvli a1, zero, e32, m2, ta, ma
-; RV32-NEXT:    vmulh.vx v8, v8, a0
-; RV32-NEXT:    ret
-;
-; RV64-LABEL: vmulh_vi_nxv4i32_0:
-; RV64:       # %bb.0:
-; RV64-NEXT:    li a0, 1
-; RV64-NEXT:    slli a0, a0, 32
-; RV64-NEXT:    addi a0, a0, -7
-; RV64-NEXT:    vsetvli a1, zero, e32, m2, ta, ma
-; RV64-NEXT:    vmulh.vx v8, v8, a0
-; RV64-NEXT:    ret
+; CHECK-LABEL: vmulh_vi_nxv4i32_0:
+; CHECK:       # %bb.0:
+; CHECK-NEXT:    li a0, -7
+; CHECK-NEXT:    vsetvli a1, zero, e32, m2, ta, ma
+; CHECK-NEXT:    vmulh.vx v8, v8, a0
+; CHECK-NEXT:    ret
   %head1 = insertelement <vscale x 4 x i32> poison, i32 -7, i32 0
   %splat1 = shufflevector <vscale x 4 x i32> %head1, <vscale x 4 x i32> poison, <vscale x 4 x i32> zeroinitializer
   %vb = sext <vscale x 4 x i32> %splat1 to <vscale x 4 x i64>
@@ -303,21 +276,12 @@ define <vscale x 8 x i32> @vmulh_vx_nxv8i32(<vscale x 8 x i32> %va, i32 %x) {
 }
 
 define <vscale x 8 x i32> @vmulh_vi_nxv8i32_0(<vscale x 8 x i32> %va) {
-; RV32-LABEL: vmulh_vi_nxv8i32_0:
-; RV32:       # %bb.0:
-; RV32-NEXT:    li a0, -7
-; RV32-NEXT:    vsetvli a1, zero, e32, m4, ta, ma
-; RV32-NEXT:    vmulh.vx v8, v8, a0
-; RV32-NEXT:    ret
-;
-; RV64-LABEL: vmulh_vi_nxv8i32_0:
-; RV64:       # %bb.0:
-; RV64-NEXT:    li a0, 1
-; RV64-NEXT:    slli a0, a0, 32
-; RV64-NEXT:    addi a0, a0, -7
-; RV64-NEXT:    vsetvli a1, zero, e32, m4, ta, ma
-; RV64-NEXT:    vmulh.vx v8, v8, a0
-; RV64-NEXT:    ret
+; CHECK-LABEL: vmulh_vi_nxv8i32_0:
+; CHECK:       # %bb.0:
+; CHECK-NEXT:    li a0, -7
+; CHECK-NEXT:    vsetvli a1, zero, e32, m4, ta, ma
+; CHECK-NEXT:    vmulh.vx v8, v8, a0
+; CHECK-NEXT:    ret
   %head1 = insertelement <vscale x 8 x i32> poison, i32 -7, i32 0
   %splat1 = shufflevector <vscale x 8 x i32> %head1, <vscale x 8 x i32> poison, <vscale x 8 x i32> zeroinitializer
   %vb = sext <vscale x 8 x i32> %splat1 to <vscale x 8 x i64>
@@ -348,3 +312,6 @@ define <vscale x 8 x i32> @vmulh_vi_nxv8i32_1(<vscale x 8 x i32> %va) {
   %vf = trunc <vscale x 8 x i64> %ve to <vscale x 8 x i32>
   ret <vscale x 8 x i32> %vf
 }
+;; NOTE: These prefixes are unused and the list is autogenerated. Do not add tests below this line:
+; RV32: {{.*}}
+; RV64: {{.*}}
diff --git a/llvm/test/CodeGen/RISCV/rvv/vmulhu-sdnode.ll b/llvm/test/CodeGen/RISCV/rvv/vmulhu-sdnode.ll
index 186d56b1293dbef..5354c17fd2a7d7c 100644
--- a/llvm/test/CodeGen/RISCV/rvv/vmulhu-sdnode.ll
+++ b/llvm/test/CodeGen/RISCV/rvv/vmulhu-sdnode.ll
@@ -37,21 +37,12 @@ define <vscale x 1 x i32> @vmulhu_vx_nxv1i32(<vscale x 1 x i32> %va, i32 %x) {
 }
 
 define <vscale x 1 x i32> @vmulhu_vi_nxv1i32_0(<vscale x 1 x i32> %va) {
-; RV32-LABEL: vmulhu_vi_nxv1i32_0:
-; RV32:       # %bb.0:
-; RV32-NEXT:    li a0, -7
-; RV32-NEXT:    vsetvli a1, zero, e32, mf2, ta, ma
-; RV32-NEXT:    vmulhu.vx v8, v8, a0
-; RV32-NEXT:    ret
-;
-; RV64-LABEL: vmulhu_vi_nxv1i32_0:
-; RV64:       # %bb.0:
-; RV64-NEXT:    li a0, 1
-; RV64-NEXT:    slli a0, a0, 32
-; RV64-NEXT:    addi a0, a0, -7
-; RV64-NEXT:    vsetvli a1, zero, e32, mf2, ta, ma
-; RV64-NEXT:    vmulhu.vx v8, v8, a0
-; RV64-NEXT:    ret
+; CHECK-LABEL: vmulhu_vi_nxv1i32_0:
+; CHECK:       # %bb.0:
+; CHECK-NEXT:    li a0, -7
+; CHECK-NEXT:    vsetvli a1, zero, e32, mf2, ta, ma
+; CHECK-NEXT:    vmulhu.vx v8, v8, a0
+; CHECK-NEXT:    ret
   %head1 = insertelement <vscale x 1 x i32> poison, i32 -7, i32 0
   %splat1 = shufflevector <vscale x 1 x i32> %head1, <vscale x 1 x i32> poison, <vscale x 1 x i32> zeroinitializer
   %vb = zext <vscale x 1 x i32> %splat1 to <vscale x 1 x i64>
@@ -124,21 +115,12 @@ define <vscale x 2 x i32> @vmulhu_vx_nxv2i32(<vscale x 2 x i32> %va, i32 %x) {
 }
 
 define <vscale x 2 x i32> @vmulhu_vi_nxv2i32_0(<vscale x 2 x i32> %va) {
-; RV32-LABEL: vmulhu_vi_nxv2i32_0:
-; RV32:       # %bb.0:
-; RV32-NEXT:    li a0, -7
-; RV32-NEXT:    vsetvli a1, zero, e32, m1, ta, ma
-; RV32-NEXT:    vmulhu.vx v8, v8, a0
-; RV32-NEXT:    ret
-;
-; RV64-LABEL: vmulhu_vi_nxv2i32_0:
-; RV64:       # %bb.0:
-; RV64-NEXT:    li a0, 1
-; RV64-NEXT:    slli a0, a0, 32
-; RV64-NEXT:    addi a0, a0, -7
-; RV64-NEXT:    vsetvli a1, zero, e32, m1, ta, ma
-; RV64-NEXT:    vmulhu.vx v8, v8, a0
-; RV64-NEXT:    ret
+; CHECK-LABEL: vmulhu_vi_nxv2i32_0:
+; CHECK:       # %bb.0:
+; CHECK-NEXT:    li a0, -7
+; CHECK-NEXT:    vsetvli a1, zero, e32, m1, ta, ma
+; CHECK-NEXT:    vmulhu.vx v8, v8, a0
+; CHECK-NEXT:    ret
   %head1 = insertelement <vscale x 2 x i32> poison, i32 -7, i32 0
   %splat1 = shufflevector <vscale x 2 x i32> %head1, <vscale x 2 x i32> poison, <vscale x 2 x i32> zeroinitializer
   %vb = zext <vscale x 2 x i32> %splat1 to <vscale x 2 x i64>
@@ -211,21 +193,12 @@ define <vscale x 4 x i32> @vmulhu_vx_nxv4i32(<vscale x 4 x i32> %va, i32 %x) {
 }
 
 define <vscale x 4 x i32> @vmulhu_vi_nxv4i32_0(<vscale x 4 x i32> %va) {
-; RV32-LABEL: vmulhu_vi_nxv4i32_0:
-; RV32:       # %bb.0:
-; RV32-NEXT:    li a0, -7
-; RV32-NEXT:    vsetvli a1, zero, e32, m2, ta, ma
-; RV32-NEXT:    vmulhu.vx v8, v8, a0
-; RV32-NEXT:    ret
-;
-; RV64-LABEL: vmulhu_vi_nxv4i32_0:
-; RV64:       # %bb.0:
-; RV64-NEXT:    li a0, 1
-; RV64-NEXT:    slli a0, a0, 32
-; RV64-NEXT:    addi a0, a0, -7
-; RV64-NEXT:    vsetvli a1, zero, e32, m2, ta, ma
-; RV64-NEXT:    vmulhu.vx v8, v8, a0
-; RV64-NEXT:    ret
+; CHECK-LABEL: vmulhu_vi_nxv4i32_0:
+; CHECK:       # %bb.0:
+; CHECK-NEXT:    li a0, -7
+; CHECK-NEXT:    vsetvli a1, zero, e32, m2, ta, ma
+; CHECK-NEXT:    vmulhu.vx v8, v8, a0
+; CHECK-NEXT:    ret
   %head1 = insertelement <vscale x 4 x i32> poison, i32 -7, i32 0
   %splat1 = shufflevector <vscale x 4 x i32> %head1, <vscale x 4 x i32> poison, <vscale x 4 x i32> zeroinitializer
   %vb = zext <vscale x 4 x i32> %splat1 to <vscale x 4 x i64>
@@ -298,21 +271,12 @@ define <vscale x 8 x i32> @vmulhu_vx_nxv8i32(<vscale x 8 x i32> %va, i32 %x) {
 }
 
 define <vscale x 8 x i32> @vmulhu_vi_nxv8i32_0(<vscale x 8 x i32> %va) {
-; RV32-LABEL: vmulhu_vi_nxv8i32_0:
-; RV32:       # %bb.0:
-; RV32-NEXT:    li a0, -7
-; RV32-NEXT:    vsetvli a1, zero, e32, m4, ta, ma
-; RV32-NEXT:    vmulhu.vx v8, v8, a0
-; RV32-NEXT:    ret
-;
-; RV64-LABEL: vmulhu_vi_nxv8i32_0:
-; RV64:       # %bb.0:
-; RV64-NEXT:    li a0, 1
-; RV64-NEXT:    slli a0, a0, 32
-; RV64-NEXT:    addi a0, a0, -7
-; RV64-NEXT:    vsetvli a1, zero, e32, m4, ta, ma
-; RV64-NEXT:    vmulhu.vx v8, v8, a0
-; RV64-NEXT:    ret
+; CHECK-LABEL: vmulhu_vi_nxv8i32_0:
+; CHECK:       # %bb.0:
+; CHECK-NEXT:    li a0, -7
+; CHECK-NEXT:    vsetvli a1, zero, e32, m4, ta, ma
+; CHECK-NEXT:    vmulhu.vx v8, v8, a0
+; CHECK-NEXT:    ret
   %head1 = insertelement <vscale x 8 x i32> poison, i32 -7, i32 0
   %splat1 = shufflevector <vscale x 8 x i32> %head1, <vscale x 8 x i32> poison, <vscale x 8 x i32> zeroinitializer
   %vb = zext <vscale x 8 x i32> %splat1 to <vscale x 8 x i64>

``````````

</details>


https://github.com/llvm/llvm-project/pull/67027


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