[RISCV] Add IsSignExtendingOpW to the Zknh SHA256 instructions.

[craig.topper]

Summary

On RV64 these instructions produce a 32-bit value and sign extend
to 64-bits.

[reames]

LGTM

llvm/lib/Target/RISCV/RISCVInstrInfoZk.td

 def AES32ESMI : RVKByteSelect<0b10011, "aes32esmi">;
 } // Predicates = [HasStdExtZkne, IsRV32]
 
 let Predicates = [HasStdExtZkne, IsRV64] in {
 def AES64ES   : ALU_rr<0b0011001, 0b000, "aes64es">;
 def AES64ESM  : ALU_rr<0b0011011, 0b000, "aes64esm">;
 } // Predicates = [HasStdExtZkne, IsRV64]
 
-let Predicates = [HasStdExtZknh] in {
+let Predicates = [HasStdExtZknh], IsSignExtendingOpW = 1 in {
 def SHA256SIG0 : RVKUnary<0b000100000010, 0b001, "sha256sig0">;
 def SHA256SIG1 : RVKUnary<0b000100000011, 0b001, "sha256sig1">;
 def SHA256SUM0 : RVKUnary<0b000100000000, 0b001, "sha256sum0">;
 def SHA256SUM1 : RVKUnary<0b000100000001, 0b001, "sha256sum1">;
 } // Predicates = [HasStdExtZknh]
 
 let Predicates = [HasStdExtZknh, IsRV32] in {
 def SHA512SIG0H : ALU_rr<0b0101110, 0b000, "sha512sig0h">;

llvm/test/CodeGen/RISCV/sextw-removal.ll

 ; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
-; RUN: llc < %s -mtriple=riscv64 -mattr=+m,+f -target-abi=lp64f \
+; RUN: llc < %s -mtriple=riscv64 -mattr=+m,+f,+zknh -target-abi=lp64f \
 ; RUN:   | FileCheck %s --check-prefixes=CHECK,RV64I
-; RUN: llc < %s -mtriple=riscv64 -mattr=+m,+zbb,+f -target-abi=lp64f \
+; RUN: llc < %s -mtriple=riscv64 -mattr=+m,+zbb,+f,+zknh -target-abi=lp64f \
 ; RUN:   | FileCheck %s --check-prefixes=CHECK,RV64ZBB
-; RUN: llc < %s -mtriple=riscv64 -mattr=+m,+zbb,+f -target-abi=lp64f \
+; RUN: llc < %s -mtriple=riscv64 -mattr=+m,+zbb,+f,+zknh -target-abi=lp64f \
 ; RUN:   -riscv-disable-sextw-removal | FileCheck %s --check-prefix=NOREMOVAL
 
 define void @test1(i32 signext %arg, i32 signext %arg1) nounwind {
 ; CHECK-LABEL: test1:
 ; CHECK:       # %bb.0: # %bb
 ; CHECK-NEXT:    addi sp, sp, -32
 ; CHECK-NEXT:    sd ra, 24(sp) # 8-byte Folded Spill
 ; CHECK-NEXT:    sd s0, 16(sp) # 8-byte Folded Spill
bb2:                                              ; preds = %bb2, %bb
   %i5 = shl i32 %i3, %arg1
   %i6 = icmp eq i32 %i4, 0
   br i1 %i6, label %bb7, label %bb2
 
 bb7:                                              ; preds = %bb2
   ret void
 }
 declare zeroext i16 @bat(i32 signext)
+
+define void @test18(i32 signext %arg, i32 signext %arg1) nounwind {
+; CHECK-LABEL: test18:
+; CHECK:       # %bb.0: # %bb
+; CHECK-NEXT:    addi sp, sp, -32
+; CHECK-NEXT:    sd ra, 24(sp) # 8-byte Folded Spill
+; CHECK-NEXT:    sd s0, 16(sp) # 8-byte Folded Spill
+; CHECK-NEXT:    sd s1, 8(sp) # 8-byte Folded Spill
+; CHECK-NEXT:    mv s0, a1
+; CHECK-NEXT:    sha256sig0 s1, a1
+; CHECK-NEXT:  .LBB21_1: # %bb2
+; CHECK-NEXT:    # =>This Inner Loop Header: Depth=1
+; CHECK-NEXT:    mv a0, s1
+; CHECK-NEXT:    call bar@plt
+; CHECK-NEXT:    sllw s1, s1, s0
+; CHECK-NEXT:    bnez a0, .LBB21_1
+; CHECK-NEXT:  # %bb.2: # %bb7
+; CHECK-NEXT:    ld ra, 24(sp) # 8-byte Folded Reload
+; CHECK-NEXT:    ld s0, 16(sp) # 8-byte Folded Reload
+; CHECK-NEXT:    ld s1, 8(sp) # 8-byte Folded Reload
+; CHECK-NEXT:    addi sp, sp, 32
+; CHECK-NEXT:    ret
+;
+; NOREMOVAL-LABEL: test18:
+; NOREMOVAL:       # %bb.0: # %bb
+; NOREMOVAL-NEXT:    addi sp, sp, -32
+; NOREMOVAL-NEXT:    sd ra, 24(sp) # 8-byte Folded Spill
+; NOREMOVAL-NEXT:    sd s0, 16(sp) # 8-byte Folded Spill
+; NOREMOVAL-NEXT:    sd s1, 8(sp) # 8-byte Folded Spill
+; NOREMOVAL-NEXT:    mv s0, a1
+; NOREMOVAL-NEXT:    sha256sig0 s1, a1
+; NOREMOVAL-NEXT:  .LBB21_1: # %bb2
+; NOREMOVAL-NEXT:    # =>This Inner Loop Header: Depth=1
+; NOREMOVAL-NEXT:    sext.w a0, s1
+; NOREMOVAL-NEXT:    call bar@plt
+; NOREMOVAL-NEXT:    sllw s1, s1, s0
+; NOREMOVAL-NEXT:    bnez a0, .LBB21_1
+; NOREMOVAL-NEXT:  # %bb.2: # %bb7
+; NOREMOVAL-NEXT:    ld ra, 24(sp) # 8-byte Folded Reload
+; NOREMOVAL-NEXT:    ld s0, 16(sp) # 8-byte Folded Reload
+; NOREMOVAL-NEXT:    ld s1, 8(sp) # 8-byte Folded Reload
+; NOREMOVAL-NEXT:    addi sp, sp, 32
+; NOREMOVAL-NEXT:    ret
+bb:
+  %sext = sext i32 %arg1 to i64
+  %i = call i64 @llvm.riscv.sha256sig0.i64(i64 %sext)
+  %trunc = trunc i64 %i to i32
+  br label %bb2
+
+bb2:                                              ; preds = %bb2, %bb
+  %i3 = phi i32 [ %trunc, %bb ], [ %i5, %bb2 ]
+  %i4 = tail call signext i32 @bar(i32 signext %i3)
+  %i5 = shl i32 %i3, %arg1
+  %i6 = icmp eq i32 %i4, 0
+  br i1 %i6, label %bb7, label %bb2
+
+bb7:                                              ; preds = %bb2
+  ret void
+}
+declare i64 @llvm.riscv.sha256sig0.i64(i64)