Merge branch 'main' into minnum_ieee_ppc

Author: wzssyqa

llvm/lib/Target/RISCV/RISCVISelDAGToDAG.cpp

@@ -653,7 +653,9 @@ bool RISCVDAGToDAGISel::trySignedBitfieldExtract(SDNode *Node) {
       return false;
 
     const unsigned Msb = ExtSize - 1;
-    const unsigned Lsb = RightShAmt;
+    // If the shift-right amount is greater than Msb, it means that extracts
+    // the X[Msb] bit and sign-extend it.
+    const unsigned Lsb = RightShAmt > Msb ? Msb : RightShAmt;
 
     SDNode *TH_EXT = BitfieldExtract(N0, Msb, Lsb, DL, VT);
     ReplaceNode(Node, TH_EXT);

llvm/test/CodeGen/RISCV/rv32xtheadbb.ll

@@ -401,6 +401,38 @@ define i64 @no_sexth_i64(i64 %a) nounwind {
   ret i64 %shr
 }
 
+define i32 @sext_sextinreg_sra(i16 %a) nounwind {
+; RV32I-LABEL: sext_sextinreg_sra:
+; RV32I:       # %bb.0:
+; RV32I-NEXT:    slli a0, a0, 16
+; RV32I-NEXT:    srai a0, a0, 26
+; RV32I-NEXT:    ret
+;
+; RV32XTHEADBB-LABEL: sext_sextinreg_sra:
+; RV32XTHEADBB:       # %bb.0:
+; RV32XTHEADBB-NEXT:    th.ext a0, a0, 15, 10
+; RV32XTHEADBB-NEXT:    ret
+  %sext = sext i16 %a to i32
+  %shr = ashr exact i32 %sext, 10
+  ret i32 %shr
+}
+
+define i32 @sext_sextinreg_sra_2(i16 %a) nounwind {
+; RV32I-LABEL: sext_sextinreg_sra_2:
+; RV32I:       # %bb.0:
+; RV32I-NEXT:    slli a0, a0, 16
+; RV32I-NEXT:    srai a0, a0, 31
+; RV32I-NEXT:    ret
+;
+; RV32XTHEADBB-LABEL: sext_sextinreg_sra_2:
+; RV32XTHEADBB:       # %bb.0:
+; RV32XTHEADBB-NEXT:    th.ext a0, a0, 15, 15
+; RV32XTHEADBB-NEXT:    ret
+  %sext = sext i16 %a to i32
+  %shr = ashr exact i32 %sext, 24
+  ret i32 %shr
+}
+
 define i32 @zexth_i32(i32 %a) nounwind {
 ; RV32I-LABEL: zexth_i32:
 ; RV32I:       # %bb.0:

llvm/test/CodeGen/RISCV/selectcc-to-shiftand.ll

@@ -263,7 +263,6 @@ define i64 @sel_shift_bool_i64(i1 %t) {
   ret i64 %shl
 }
 
-; FIXME: This should use sraiw+and
 define i64 @sraiw_andi(i32 signext %0, i32 signext %1) nounwind {
 ; RV32-LABEL: sraiw_andi:
 ; RV32:       # %bb.0: # %entry