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aarch64 isel: collect_address_addends: correctly handle ExtendOp::UXTW(negative immediate).

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The current code doesn't correctly handle the case where `ExtendOp::UXTW` has
as source, a constant-producing insn that produces a negative (32-bit) value.
Then the value is incorrectly sign-extended to 64 bits (in fact, this has
already been done by `ctx.get_constant(insn)`), whereas it needs to be zero
extended.  The obvious fix, done here, is just to force bits 63:32 of the
extension to zero, hence zero-extending it.
This commit is contained in:
Julian Seward
2020-12-04 18:29:39 +01:00
committed by julian-seward1
parent d07fffeb41
commit 8f34d2dc59
2 changed files with 67 additions and 1 deletions
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2
cranelift/codegen/src/isa/aarch64/lower.rs
View File

@@ -616,7 +616,7 @@ fn collect_address_addends<C: LowerCtx<I = Inst>>(
maybe_input_insn(ctx, extendee_input, Opcode::Iconst),
extendop,
) {
let value = ctx.get_constant(insn).unwrap() as i64;
let value = (ctx.get_constant(insn).unwrap() & 0xFFFF_FFFF_u64) as i64;
offset += value;
} else {
let reg = put_input_in_reg(ctx, extendee_input, NarrowValueMode::None);

66
cranelift/filetests/filetests/isa/aarch64/amodes.clif
View File

@@ -344,3 +344,69 @@ block0(v0: i64, v1: i32):
; nextln: mov sp, fp
; nextln: ldp fp, lr, [sp], #16
; nextln: ret
function %f18(i64, i64, i64) -> i32 {
block0(v0: i64, v1: i64, v2: i64):
v3 = iconst.i32 -4098
v6 = uextend.i64 v3
v5 = sload16.i32 v6+0
return v5
}
; check: stp fp, lr, [sp, #-16]!
; nextln: mov fp, sp
; nextln: movn w0, #4097
; nextln: ldrsh x0, [x0]
; nextln: mov sp, fp
; nextln: ldp fp, lr, [sp], #16
; nextln: ret
function %f19(i64, i64, i64) -> i32 {
block0(v0: i64, v1: i64, v2: i64):
v3 = iconst.i32 4098
v6 = uextend.i64 v3
v5 = sload16.i32 v6+0
return v5
}
; check: stp fp, lr, [sp, #-16]!
; nextln: mov fp, sp
; nextln: movz x0, #4098
; nextln: ldrsh x0, [x0]
; nextln: mov sp, fp
; nextln: ldp fp, lr, [sp], #16
; nextln: ret
function %f20(i64, i64, i64) -> i32 {
block0(v0: i64, v1: i64, v2: i64):
v3 = iconst.i32 -4098
v6 = sextend.i64 v3
v5 = sload16.i32 v6+0
return v5
}
; check: stp fp, lr, [sp, #-16]!
; nextln: mov fp, sp
; nextln: movn w0, #4097
; nextln: sxtw x0, w0
; nextln: ldrsh x0, [x0]
; nextln: mov sp, fp
; nextln: ldp fp, lr, [sp], #16
; nextln: ret
function %f21(i64, i64, i64) -> i32 {
block0(v0: i64, v1: i64, v2: i64):
v3 = iconst.i32 4098
v6 = sextend.i64 v3
v5 = sload16.i32 v6+0
return v5
}
; check: stp fp, lr, [sp, #-16]!
; nextln: mov fp, sp
; nextln: movz x0, #4098
; nextln: sxtw x0, w0
; nextln: ldrsh x0, [x0]
; nextln: mov sp, fp
; nextln: ldp fp, lr, [sp], #16
; nextln: ret