AMDGPU/SI: Remove zero_extend patterns for i16 ops selected to 32-bit insts

[• tstellarAMD]

Summary

The 32-bit instructions don't zero the high 16-bits like the 16-bit
instructions do.

[arsenm]

LGTM

lib/Target/AMDGPU/VOP2Instructions.td

 defm : Arithmetic_i16_Pats<add, V_ADD_U16_e32>;
 defm : Arithmetic_i16_Pats<mul, V_MUL_LO_U16_e32>;
 defm : Arithmetic_i16_Pats<sub, V_SUB_U16_e32>;
 defm : Arithmetic_i16_Pats<smin, V_MIN_I16_e32>;
 defm : Arithmetic_i16_Pats<smax, V_MAX_I16_e32>;
 defm : Arithmetic_i16_Pats<umin, V_MIN_U16_e32>;
 defm : Arithmetic_i16_Pats<umax, V_MAX_U16_e32>;
 
-defm : Arithmetic_i16_Pats<and, V_AND_B32_e32>;
-defm : Arithmetic_i16_Pats<or, V_OR_B32_e32>;
-defm : Arithmetic_i16_Pats<xor, V_XOR_B32_e32>;
+def : Pat <
+  (and i16:$src0, i16:$src1),
+  (V_AND_B32_e32 $src0, $src1)
+>;
+
+def : Pat <
+  (or i16:$src0, i16:$src1),
+  (V_OR_B32_e32 $src0, $src1)
+>;
+
+def : Pat <
+  (xor i16:$src0, i16:$src1),
+  (V_XOR_B32_e32 $src0, $src1)
+>;
 
 defm : Bits_OpsRev_i16_Pats<shl, V_LSHLREV_B16_e32>;
 defm : Bits_OpsRev_i16_Pats<srl, V_LSHRREV_B16_e32>;
 defm : Bits_OpsRev_i16_Pats<sra, V_ASHRREV_B16_e32>;
 
 def : ZExt_i16_i1_Pat<zext>;
 def : ZExt_i16_i1_Pat<anyext>;
 

test/CodeGen/AMDGPU/extend-bit-ops-i16.ll

+; RUN: llc < %s -march=amdgcn -mcpu=tonga -verify-machineinstrs | FileCheck %s --check-prefix=GCN
+
+; GCN-LABEL: and_zext:
+; GCN: v_and_b32_e32 [[VAL16:v[0-9]+]], v{{[0-9]+}}, v{{[0-9]+}}
+; GCN: v_and_b32_e32 v{{[0-9]+}}, 0xffff, [[VAL16]]
+define void @and_zext(i32 addrspace(1)* %out, i16 addrspace(1)* %in) {
+  %id = call i32 @llvm.amdgcn.workitem.id.x() #1
+  %ptr = getelementptr i16, i16 addrspace(1)* %in, i32 %id
+  %a = load i16, i16 addrspace(1)* %in
+  %b = load i16, i16 addrspace(1)* %ptr
+  %c = add i16 %a, %b
+  %val16 = and i16 %c, %a
+  %val32 = zext i16 %val16 to i32
+  store i32 %val32, i32 addrspace(1)* %out
+  ret void
+}
+
+; GCN-LABEL: or_zext:
+; GCN: v_or_b32_e32 [[VAL16:v[0-9]+]], v{{[0-9]+}}, v{{[0-9]+}}
+; GCN: v_and_b32_e32 v{{[0-9]+}}, 0xffff, [[VAL16]]
+define void @or_zext(i32 addrspace(1)* %out, i16 addrspace(1)* %in) {
+  %id = call i32 @llvm.amdgcn.workitem.id.x() #1
+  %ptr = getelementptr i16, i16 addrspace(1)* %in, i32 %id
+  %a = load i16, i16 addrspace(1)* %in
+  %b = load i16, i16 addrspace(1)* %ptr
+  %c = add i16 %a, %b
+  %val16 = or i16 %c, %a
+  %val32 = zext i16 %val16 to i32
+  store i32 %val32, i32 addrspace(1)* %out
+  ret void
+}
+
+; GCN-LABEL: xor_zext:
+; GCN: v_xor_b32_e32 [[VAL16:v[0-9]+]], v{{[0-9]+}}, v{{[0-9]+}}
+; GCN: v_and_b32_e32 v{{[0-9]+}}, 0xffff, [[VAL16]]
+define void @xor_zext(i32 addrspace(1)* %out, i16 addrspace(1)* %in) {
+  %id = call i32 @llvm.amdgcn.workitem.id.x() #1
+  %ptr = getelementptr i16, i16 addrspace(1)* %in, i32 %id
+  %a = load i16, i16 addrspace(1)* %in
+  %b = load i16, i16 addrspace(1)* %ptr
+  %c = add i16 %a, %b
+  %val16 = xor i16 %c, %a
+  %val32 = zext i16 %val16 to i32
+  store i32 %val32, i32 addrspace(1)* %out
+  ret void
+}
+
+declare i32 @llvm.amdgcn.workitem.id.x() #1
+
+attributes #1 = { nounwind readnone }