Index: lib/Target/SystemZ/SystemZInstrInfo.td =================================================================== --- lib/Target/SystemZ/SystemZInstrInfo.td +++ lib/Target/SystemZ/SystemZInstrInfo.td @@ -1022,7 +1022,7 @@ // ANDs of memory. let CCValues = 0xC, CompareZeroCCMask = 0x8 in { defm N : BinaryRXPair<"n", 0x54, 0xE354, and, GR32, load, 4>; - def NG : BinaryRXY<"ng", 0xE380, and, GR64, load, 8>; + def NG : BinaryRXY<"ng", 0xE380, and, GR64, load, 8>; } // AND to memory @@ -1680,6 +1680,31 @@ (i32 63)), (Select64 (LGHI -1), (LGHI 0), imm32zx4:$valid, imm32zx4:$cc)>; +// Shift instructions only use the last 6 bits of the second operand register, +// so we can safely use NILL (16 fewer bits than NILF) to only AND the last 16 +// bits. +// Complexity is added so that we match this before we match NILF on the AND +// operation alone. +let AddedComplexity = 4 in { + def : Pat<(shl GR32:$val, (and GR32:$shift, uimm32:$imm)), + (SLL GR32:$val, (NILL GR32:$shift, uimm32:$imm), 0)>; + + def : Pat<(sra GR32:$val, (and GR32:$shift, uimm32:$imm)), + (SRA GR32:$val, (NILL GR32:$shift, uimm32:$imm), 0)>; + + def : Pat<(srl GR32:$val, (and GR32:$shift, uimm32:$imm)), + (SRL GR32:$val, (NILL GR32:$shift, uimm32:$imm), 0)>; + + def : Pat<(shl GR64:$val, (and GR32:$shift, uimm32:$imm)), + (SLLG GR64:$val, (NILL GR32:$shift, uimm32:$imm), 0)>; + + def : Pat<(sra GR64:$val, (and GR32:$shift, uimm32:$imm)), + (SRAG GR64:$val, (NILL GR32:$shift, uimm32:$imm), 0)>; + + def : Pat<(srl GR64:$val, (and GR32:$shift, uimm32:$imm)), + (SRLG GR64:$val, (NILL GR32:$shift, uimm32:$imm), 0)>; +} + // Peepholes for turning scalar operations into block operations. defm : BlockLoadStore; Index: test/CodeGen/SystemZ/shift-11.ll =================================================================== --- /dev/null +++ test/CodeGen/SystemZ/shift-11.ll @@ -0,0 +1,63 @@ +; Test shortening of NILL to NILF when the result is used as a shift amount. +; +; RUN: llc < %s -mtriple=s390x-linux-gnu | FileCheck %s + +; Test logical shift right. +define i32 @f1(i32 %a, i32 %sh) { +; CHECK-LABEL: f1: +; CHECK: nill %r3, 31 +; CHECK: srl %r2, 0(%r3) + %and = and i32 %sh, 31 + %shift = lshr i32 %a, %and + ret i32 %shift +} + +; Test arithmetic shift right. +define i32 @f2(i32 %a, i32 %sh) { +; CHECK-LABEL: f2: +; CHECK: nill %r3, 31 +; CHECK: sra %r2, 0(%r3) + %and = and i32 %sh, 31 + %shift = ashr i32 %a, %and + ret i32 %shift +} + +; Test shift left. +define i32 @f3(i32 %a, i32 %sh) { +; CHECK-LABEL: f3: +; CHECK: nill %r3, 31 +; CHECK: sll %r2, 0(%r3) + %and = and i32 %sh, 31 + %shift = shl i32 %a, %and + ret i32 %shift +} + +; Test 64-bit logical shift right. +define i64 @f4(i64 %a, i64 %sh) { +; CHECK-LABEL: f4: +; CHECK: nill %r3, 31 +; CHECK: srlg %r2, %r2, 0(%r3) + %and = and i64 %sh, 31 + %shift = lshr i64 %a, %and + ret i64 %shift +} + +; Test 64-bit arithmetic shift right. +define i64 @f5(i64 %a, i64 %sh) { +; CHECK-LABEL: f5: +; CHECK: nill %r3, 31 +; CHECK: srag %r2, %r2, 0(%r3) + %and = and i64 %sh, 31 + %shift = ashr i64 %a, %and + ret i64 %shift +} + +; Test 64-bit shift left. +define i64 @f6(i64 %a, i64 %sh) { +; CHECK-LABEL: f6: +; CHECK: nill %r3, 31 +; CHECK: sllg %r2, %r2, 0(%r3) + %and = and i64 %sh, 31 + %shift = shl i64 %a, %and + ret i64 %shift +}