diff options
| -rw-r--r-- | llvm/lib/Target/AArch64/AArch64InstrFormats.td | 2 | ||||
| -rw-r--r-- | llvm/test/CodeGen/AArch64/addsub.ll | 28 |
2 files changed, 30 insertions, 0 deletions
diff --git a/llvm/lib/Target/AArch64/AArch64InstrFormats.td b/llvm/lib/Target/AArch64/AArch64InstrFormats.td index d295c028ec4..a91cf3bebb9 100644 --- a/llvm/lib/Target/AArch64/AArch64InstrFormats.td +++ b/llvm/lib/Target/AArch64/AArch64InstrFormats.td @@ -1637,10 +1637,12 @@ multiclass AddSub<bit isSub, string mnemonic, SDPatternOperator OpNode = null_frag> { let hasSideEffects = 0, isReMaterializable = 1, isAsCheapAsAMove = 1 in { // Add/Subtract immediate + let AddedComplexity = 6 in def Wri : BaseAddSubImm<isSub, 0, GPR32sp, GPR32sp, addsub_shifted_imm32, mnemonic, OpNode> { let Inst{31} = 0; } + let AddedComplexity = 6 in def Xri : BaseAddSubImm<isSub, 0, GPR64sp, GPR64sp, addsub_shifted_imm64, mnemonic, OpNode> { let Inst{31} = 1; diff --git a/llvm/test/CodeGen/AArch64/addsub.ll b/llvm/test/CodeGen/AArch64/addsub.ll index 09b9f629973..d6350a6db0e 100644 --- a/llvm/test/CodeGen/AArch64/addsub.ll +++ b/llvm/test/CodeGen/AArch64/addsub.ll @@ -24,6 +24,34 @@ define void @add_small() { ret void } +; Make sure we grab the imm variant when the register operand +; can be implicitly zero-extend. +; We used to generate something horrible like this: +; wA = ldrb +; xB = ldimm 12 +; xC = add xB, wA, uxtb +; whereas this can be achieved with: +; wA = ldrb +; xC = add xA, #12 ; <- xA implicitly zero extend wA. +define void @add_small_imm(i8* %p, i64* %q, i32 %b, i32* %addr) { +; CHECK-LABEL: add_small_imm: +entry: + +; CHECK: ldrb w[[LOAD32:[0-9]+]], [x0] + %t = load i8, i8* %p + %promoted = zext i8 %t to i64 + %zextt = zext i8 %t to i32 + %add = add nuw i32 %zextt, %b + +; CHECK: add [[ADD2:x[0-9]+]], x[[LOAD32]], #12 + %add2 = add nuw i64 %promoted, 12 + store i32 %add, i32* %addr + +; CHECK: str [[ADD2]], [x1] + store i64 %add2, i64* %q + ret void +} + ; Add 12-bit immediates, shifted left by 12 bits define void @add_med() { ; CHECK-LABEL: add_med: |
