[llvm] c986d47 - AMDGPU: Update reqd-work-group-size optimization for umin intrinsic

Matt Arsenault via llvm-commits llvm-commits at lists.llvm.org
Tue Apr 12 17:03:07 PDT 2022


Author: Matt Arsenault
Date: 2022-04-12T20:03:02-04:00
New Revision: c986d476cd090fb8a535f02df02c280e7a815d2d

URL: https://github.com/llvm/llvm-project/commit/c986d476cd090fb8a535f02df02c280e7a815d2d
DIFF: https://github.com/llvm/llvm-project/commit/c986d476cd090fb8a535f02df02c280e7a815d2d.diff

LOG: AMDGPU: Update reqd-work-group-size optimization for umin intrinsic

This code was pattern matching the ID computation expression as it
appears in the library. This was a compare and select, but now that
umin is canonical, we were no longer matching. Update to match the
intrinsic instead.

Added: 
    

Modified: 
    llvm/lib/Target/AMDGPU/AMDGPULowerKernelAttributes.cpp
    llvm/test/CodeGen/AMDGPU/reqd-work-group-size.ll

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Target/AMDGPU/AMDGPULowerKernelAttributes.cpp b/llvm/lib/Target/AMDGPU/AMDGPULowerKernelAttributes.cpp
index 08a1b970648df..f5903b3afb816 100644
--- a/llvm/lib/Target/AMDGPU/AMDGPULowerKernelAttributes.cpp
+++ b/llvm/lib/Target/AMDGPU/AMDGPULowerKernelAttributes.cpp
@@ -163,39 +163,29 @@ static bool processUse(CallInst *CI) {
     if (!GroupSize || !GridSize)
       continue;
 
+    using namespace llvm::PatternMatch;
+    auto GroupIDIntrin =
+        I == 0 ? m_Intrinsic<Intrinsic::amdgcn_workgroup_id_x>()
+               : (I == 1 ? m_Intrinsic<Intrinsic::amdgcn_workgroup_id_y>()
+                         : m_Intrinsic<Intrinsic::amdgcn_workgroup_id_z>());
+
     for (User *U : GroupSize->users()) {
       auto *ZextGroupSize = dyn_cast<ZExtInst>(U);
       if (!ZextGroupSize)
         continue;
 
-      for (User *ZextUser : ZextGroupSize->users()) {
-        auto *SI = dyn_cast<SelectInst>(ZextUser);
-        if (!SI)
-          continue;
-
-        using namespace llvm::PatternMatch;
-        auto GroupIDIntrin = I == 0 ?
-          m_Intrinsic<Intrinsic::amdgcn_workgroup_id_x>() :
-            (I == 1 ? m_Intrinsic<Intrinsic::amdgcn_workgroup_id_y>() :
-                      m_Intrinsic<Intrinsic::amdgcn_workgroup_id_z>());
-
-        auto SubExpr = m_Sub(m_Specific(GridSize),
-                             m_Mul(GroupIDIntrin, m_Specific(ZextGroupSize)));
-
-        ICmpInst::Predicate Pred;
-        if (match(SI,
-                  m_Select(m_ICmp(Pred, SubExpr, m_Specific(ZextGroupSize)),
-                           SubExpr,
-                           m_Specific(ZextGroupSize))) &&
-            Pred == ICmpInst::ICMP_ULT) {
+      for (User *UMin : ZextGroupSize->users()) {
+        if (match(UMin,
+                  m_UMin(m_Sub(m_Specific(GridSize),
+                               m_Mul(GroupIDIntrin, m_Specific(ZextGroupSize))),
+                         m_Specific(ZextGroupSize)))) {
           if (HasReqdWorkGroupSize) {
             ConstantInt *KnownSize
               = mdconst::extract<ConstantInt>(MD->getOperand(I));
-            SI->replaceAllUsesWith(ConstantExpr::getIntegerCast(KnownSize,
-                                                                SI->getType(),
-                                                                false));
+            UMin->replaceAllUsesWith(ConstantExpr::getIntegerCast(
+                KnownSize, UMin->getType(), false));
           } else {
-            SI->replaceAllUsesWith(ZextGroupSize);
+            UMin->replaceAllUsesWith(ZextGroupSize);
           }
 
           MadeChange = true;

diff  --git a/llvm/test/CodeGen/AMDGPU/reqd-work-group-size.ll b/llvm/test/CodeGen/AMDGPU/reqd-work-group-size.ll
index bb68d7d8fb6a5..8bbbf504ec0ce 100644
--- a/llvm/test/CodeGen/AMDGPU/reqd-work-group-size.ll
+++ b/llvm/test/CodeGen/AMDGPU/reqd-work-group-size.ll
@@ -96,9 +96,8 @@ define amdgpu_kernel void @use_local_size_x_8_16_2(i64 addrspace(1)* %out) #0 !r
   %group.size.x.zext = zext i16 %group.size.x to i32
   %group.id_x_group.size.x = mul i32 %group.id, %group.size.x.zext
   %sub = sub i32 %grid.size.x, %group.id_x_group.size.x
-  %cmp = icmp ult i32 %sub, %group.size.x.zext
-  %select = select i1 %cmp, i32 %sub, i32 %group.size.x.zext
-  %zext = zext i32 %select to i64
+  %umin = call i32 @llvm.umin.i32(i32 %sub, i32 %group.size.x.zext)
+  %zext = zext i32 %umin to i64
   store i64 %zext, i64 addrspace(1)* %out
   ret void
 }
@@ -117,9 +116,8 @@ define amdgpu_kernel void @use_local_size_y_8_16_2(i64 addrspace(1)* %out) #0 !r
   %group.size.y.zext = zext i16 %group.size.y to i32
   %group.id_x_group.size.y = mul i32 %group.id, %group.size.y.zext
   %sub = sub i32 %grid.size.y, %group.id_x_group.size.y
-  %cmp = icmp ult i32 %sub, %group.size.y.zext
-  %select = select i1 %cmp, i32 %sub, i32 %group.size.y.zext
-  %zext = zext i32 %select to i64
+  %umin = call i32 @llvm.umin.i32(i32 %sub, i32 %group.size.y.zext)
+  %zext = zext i32 %umin to i64
   store i64 %zext, i64 addrspace(1)* %out
   ret void
 }
@@ -138,9 +136,8 @@ define amdgpu_kernel void @use_local_size_z_8_16_2(i64 addrspace(1)* %out) #0 !r
   %group.size.z.zext = zext i16 %group.size.z to i32
   %group.id_x_group.size.z = mul i32 %group.id, %group.size.z.zext
   %sub = sub i32 %grid.size.z, %group.id_x_group.size.z
-  %cmp = icmp ult i32 %sub, %group.size.z.zext
-  %select = select i1 %cmp, i32 %sub, i32 %group.size.z.zext
-  %zext = zext i32 %select to i64
+  %umin = call i32 @llvm.umin.i32(i32 %sub, i32 %group.size.z.zext)
+  %zext = zext i32 %umin to i64
   store i64 %zext, i64 addrspace(1)* %out
   ret void
 }
@@ -163,9 +160,8 @@ define amdgpu_kernel void @local_size_x_8_16_2_wrong_group_id(i64 addrspace(1)*
   %group.size.x.zext = zext i16 %group.size.x to i32
   %group.id_x_group.size.x = mul i32 %group.id, %group.size.x.zext
   %sub = sub i32 %grid.size.x, %group.id_x_group.size.x
-  %cmp = icmp ult i32 %sub, %group.size.x.zext
-  %select = select i1 %cmp, i32 %sub, i32 %group.size.x.zext
-  %zext = zext i32 %select to i64
+  %umin = call i32 @llvm.umin.i32(i32 %sub, i32 %group.size.x.zext)
+  %zext = zext i32 %umin to i64
   store i64 %zext, i64 addrspace(1)* %out
   ret void
 }
@@ -186,9 +182,8 @@ define amdgpu_kernel void @local_size_x_8_16_2_wrong_group_id(i64 addrspace(1)*
   %group.size.x.zext = zext i16 %group.size.x to i32
   %group.id_x_group.size.x = mul i32 %group.id, %group.size.x.zext
   %sub = sub i32 %grid.size.x, %group.id_x_group.size.x
-  %cmp = icmp ult i32 %sub, %group.size.x.zext
-  %select = select i1 %cmp, i32 %sub, i32 %group.size.x.zext
-  %zext = zext i32 %select to i64
+  %umin = call i32 @llvm.umin.i32(i32 %sub, i32 %group.size.x.zext)
+  %zext = zext i32 %umin to i64
   store i64 %zext, i64 addrspace(1)* %out
   ret void
 }
@@ -198,7 +193,7 @@ define amdgpu_kernel void @local_size_x_8_16_2_wrong_group_id(i64 addrspace(1)*
 ; CHECK: %group.id = tail call i32 @llvm.amdgcn.workgroup.id.x()
 ; CHECK: %group.id_x_group.size.x.neg = mul i32 %group.id, -8
 ; CHECK: %sub = add i32 %group.id_x_group.size.x.neg, %grid.size.x
-; CHECK: %1 = call i32 @llvm.smin.i32(i32 %sub, i32 8)
+; CHECK: %smin = call i32 @llvm.smin.i32(i32 %sub, i32 8)
 define amdgpu_kernel void @local_size_x_8_16_2_wrong_cmp_type(i64 addrspace(1)* %out) #0 !reqd_work_group_size !0 {
   %dispatch.ptr = tail call i8 addrspace(4)* @llvm.amdgcn.dispatch.ptr()
   %gep.group.size.x = getelementptr inbounds i8, i8 addrspace(4)* %dispatch.ptr, i64 4
@@ -211,9 +206,8 @@ define amdgpu_kernel void @local_size_x_8_16_2_wrong_cmp_type(i64 addrspace(1)*
   %group.size.x.zext = zext i16 %group.size.x to i32
   %group.id_x_group.size.x = mul i32 %group.id, %group.size.x.zext
   %sub = sub i32 %grid.size.x, %group.id_x_group.size.x
-  %cmp = icmp slt i32 %sub, %group.size.x.zext
-  %select = select i1 %cmp, i32 %sub, i32 %group.size.x.zext
-  %zext = zext i32 %select to i64
+  %smin = call i32 @llvm.smin.i32(i32 %sub, i32 %group.size.x.zext)
+  %zext = zext i32 %smin to i64
   store i64 %zext, i64 addrspace(1)* %out
   ret void
 }
@@ -221,8 +215,8 @@ define amdgpu_kernel void @local_size_x_8_16_2_wrong_cmp_type(i64 addrspace(1)*
 ; CHECK-LABEL: @local_size_x_8_16_2_wrong_select(
 ; CHECK: %group.id_x_group.size.x.neg = mul i32 %group.id, -8
 ; CHECK: %sub = add i32 %group.id_x_group.size.x.neg, %grid.size.x
-; CHECK: %1 = call i32 @llvm.umax.i32(i32 %sub, i32 8)
-; CHECK: %zext = zext i32 %1 to i64
+; CHECK: %umax = call i32 @llvm.umax.i32(i32 %sub, i32 8)
+; CHECK: %zext = zext i32 %umax to i64
 define amdgpu_kernel void @local_size_x_8_16_2_wrong_select(i64 addrspace(1)* %out) #0 !reqd_work_group_size !0 {
   %dispatch.ptr = tail call i8 addrspace(4)* @llvm.amdgcn.dispatch.ptr()
   %gep.group.size.x = getelementptr inbounds i8, i8 addrspace(4)* %dispatch.ptr, i64 4
@@ -235,9 +229,8 @@ define amdgpu_kernel void @local_size_x_8_16_2_wrong_select(i64 addrspace(1)* %o
   %group.size.x.zext = zext i16 %group.size.x to i32
   %group.id_x_group.size.x = mul i32 %group.id, %group.size.x.zext
   %sub = sub i32 %grid.size.x, %group.id_x_group.size.x
-  %cmp = icmp ult i32 %sub, %group.size.x.zext
-  %select = select i1 %cmp, i32 %group.size.x.zext, i32 %sub
-  %zext = zext i32 %select to i64
+  %umax = call i32 @llvm.umax.i32(i32 %sub, i32 %group.size.x.zext)
+  %zext = zext i32 %umax to i64
   store i64 %zext, i64 addrspace(1)* %out
   ret void
 }
@@ -261,9 +254,8 @@ define amdgpu_kernel void @use_local_size_x_8_16_2_wrong_grid_load_size(i64 addr
   %group.size.x.zext = zext i16 %group.size.x to i32
   %group.id_x_group.size.x = mul i32 %group.id, %group.size.x.zext
   %sub = sub i32 %grid.size.x.zext, %group.id_x_group.size.x
-  %cmp = icmp ult i32 %sub, %group.size.x.zext
-  %select = select i1 %cmp, i32 %sub, i32 %group.size.x.zext
-  %zext = zext i32 %select to i64
+  %umin = call i32 @llvm.umin.i32(i32 %sub, i32 %group.size.x.zext)
+  %zext = zext i32 %umin to i64
   store i64 %zext, i64 addrspace(1)* %out
   ret void
 }
@@ -327,9 +319,8 @@ bb25:                                             ; preds = %bb17, %bb9, %bb1, %
   %tmp29 = zext i16 %group.size to i32
   %tmp30 = mul i32 %tmp28, %tmp29
   %tmp31 = sub i32 %tmp26, %tmp30
-  %tmp32 = icmp ult i32 %tmp31, %tmp29
-  %tmp33 = select i1 %tmp32, i32 %tmp31, i32 %tmp29
-  %tmp34 = zext i32 %tmp33 to i64
+  %umin = call i32 @llvm.umin.i32(i32 %tmp31, i32 %tmp29)
+  %tmp34 = zext i32 %umin to i64
   ret i64 %tmp34
 }
 
@@ -349,9 +340,8 @@ define amdgpu_kernel void @all_local_size(i64 addrspace(1)* nocapture readnone %
   %tmp29.i = zext i16 %tmp8.i to i32
   %tmp30.i = mul i32 %tmp2.i, %tmp29.i
   %tmp31.i = sub i32 %tmp5.i, %tmp30.i
-  %tmp32.i = icmp ult i32 %tmp31.i, %tmp29.i
-  %tmp33.i = select i1 %tmp32.i, i32 %tmp31.i, i32 %tmp29.i
-  %tmp34.i = zext i32 %tmp33.i to i64
+  %umin0 = call i32 @llvm.umin.i32(i32 %tmp31.i, i32 %tmp29.i)
+  %tmp34.i = zext i32 %umin0 to i64
   %tmp10.i = tail call i32 @llvm.amdgcn.workgroup.id.y() #0
   %tmp11.i = getelementptr inbounds i8, i8 addrspace(4)* %tmp.i, i64 16
   %tmp12.i = bitcast i8 addrspace(4)* %tmp11.i to i32 addrspace(4)*
@@ -362,9 +352,8 @@ define amdgpu_kernel void @all_local_size(i64 addrspace(1)* nocapture readnone %
   %tmp29.i9 = zext i16 %tmp16.i to i32
   %tmp30.i10 = mul i32 %tmp10.i, %tmp29.i9
   %tmp31.i11 = sub i32 %tmp13.i, %tmp30.i10
-  %tmp32.i12 = icmp ult i32 %tmp31.i11, %tmp29.i9
-  %tmp33.i13 = select i1 %tmp32.i12, i32 %tmp31.i11, i32 %tmp29.i9
-  %tmp34.i14 = zext i32 %tmp33.i13 to i64
+  %umin1 = call i32 @llvm.umin.i32(i32 %tmp31.i11, i32 %tmp29.i9)
+  %tmp34.i14 = zext i32 %umin1 to i64
   %tmp18.i = tail call i32 @llvm.amdgcn.workgroup.id.z() #0
   %tmp19.i = getelementptr inbounds i8, i8 addrspace(4)* %tmp.i, i64 20
   %tmp20.i = bitcast i8 addrspace(4)* %tmp19.i to i32 addrspace(4)*
@@ -375,9 +364,8 @@ define amdgpu_kernel void @all_local_size(i64 addrspace(1)* nocapture readnone %
   %tmp29.i2 = zext i16 %tmp24.i to i32
   %tmp30.i3 = mul i32 %tmp18.i, %tmp29.i2
   %tmp31.i4 = sub i32 %tmp21.i, %tmp30.i3
-  %tmp32.i5 = icmp ult i32 %tmp31.i4, %tmp29.i2
-  %tmp33.i6 = select i1 %tmp32.i5, i32 %tmp31.i4, i32 %tmp29.i2
-  %tmp34.i7 = zext i32 %tmp33.i6 to i64
+  %umin2 = call i32 @llvm.umin.i32(i32 %tmp31.i4, i32 %tmp29.i2)
+  %tmp34.i7 = zext i32 %umin2 to i64
   store volatile i64 %tmp34.i, i64 addrspace(1)* %out, align 4
   store volatile i64 %tmp34.i14, i64 addrspace(1)* %out, align 4
   store volatile i64 %tmp34.i7, i64 addrspace(1)* %out, align 4
@@ -462,9 +450,8 @@ define amdgpu_kernel void @use_local_size_x_uniform_work_group_size(i64 addrspac
   %group.size.x.zext = zext i16 %group.size.x to i32
   %group.id_x_group.size.x = mul i32 %group.id, %group.size.x.zext
   %sub = sub i32 %grid.size.x, %group.id_x_group.size.x
-  %cmp = icmp ult i32 %sub, %group.size.x.zext
-  %select = select i1 %cmp, i32 %sub, i32 %group.size.x.zext
-  %zext = zext i32 %select to i64
+  %umin = call i32 @llvm.umin.i32(i32 %sub, i32 %group.size.x.zext)
+  %zext = zext i32 %umin to i64
   store i64 %zext, i64 addrspace(1)* %out
   ret void
 }
@@ -483,9 +470,8 @@ define amdgpu_kernel void @use_local_size_x_uniform_work_group_size_false(i64 ad
   %group.size.x.zext = zext i16 %group.size.x to i32
   %group.id_x_group.size.x = mul i32 %group.id, %group.size.x.zext
   %sub = sub i32 %grid.size.x, %group.id_x_group.size.x
-  %cmp = icmp ult i32 %sub, %group.size.x.zext
-  %select = select i1 %cmp, i32 %sub, i32 %group.size.x.zext
-  %zext = zext i32 %select to i64
+  %umin = call i32 @llvm.umin.i32(i32 %sub, i32 %group.size.x.zext)
+  %zext = zext i32 %umin to i64
   store i64 %zext, i64 addrspace(1)* %out
   ret void
 }
@@ -501,6 +487,9 @@ declare i8 addrspace(4)* @llvm.amdgcn.dispatch.ptr() #1
 declare i32 @llvm.amdgcn.workgroup.id.x() #1
 declare i32 @llvm.amdgcn.workgroup.id.y() #1
 declare i32 @llvm.amdgcn.workgroup.id.z() #1
+declare i32 @llvm.umin.i32(i32, i32) #1
+declare i32 @llvm.smin.i32(i32, i32) #1
+declare i32 @llvm.umax.i32(i32, i32) #1
 
 attributes #0 = { nounwind "uniform-work-group-size"="true" }
 attributes #1 = { nounwind readnone speculatable }


        


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