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[PULL 01/27] tcg/aarch64: Fix constant subtraction in tcg_out_addsub2
From: |
Richard Henderson |
Subject: |
[PULL 01/27] tcg/aarch64: Fix constant subtraction in tcg_out_addsub2 |
Date: |
Sat, 6 Mar 2021 13:35:47 -0800 |
An hppa guest executing
0x000000000000e05c: ldil L%10000,r4
0x000000000000e060: ldo 0(r4),r4
0x000000000000e064: sub r3,r4,sp
produces
---- 000000000000e064 000000000000e068
sub2_i32 tmp0,tmp4,r3,$0x1,$0x10000,$0x0
after folding and constant propagation. Then we hit
tcg-target.c.inc:640: tcg_out_insn_3401: Assertion `aimm <= 0xfff' failed.
because aimm is in fact -16, but unsigned.
The ((bl < 0) ^ sub) condition which negates bl is incorrect and will
always lead to this abort. If the constant is positive, sub will make
it negative; if the constant is negative, sub will keep it negative.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
tcg/aarch64/tcg-target.c.inc | 16 +++++++++-------
1 file changed, 9 insertions(+), 7 deletions(-)
diff --git a/tcg/aarch64/tcg-target.c.inc b/tcg/aarch64/tcg-target.c.inc
index 1376cdc404..ec0a86d9d8 100644
--- a/tcg/aarch64/tcg-target.c.inc
+++ b/tcg/aarch64/tcg-target.c.inc
@@ -1410,10 +1410,10 @@ static void tcg_out_addsubi(TCGContext *s, int ext,
TCGReg rd,
}
}
-static inline void tcg_out_addsub2(TCGContext *s, TCGType ext, TCGReg rl,
- TCGReg rh, TCGReg al, TCGReg ah,
- tcg_target_long bl, tcg_target_long bh,
- bool const_bl, bool const_bh, bool sub)
+static void tcg_out_addsub2(TCGContext *s, TCGType ext, TCGReg rl,
+ TCGReg rh, TCGReg al, TCGReg ah,
+ tcg_target_long bl, tcg_target_long bh,
+ bool const_bl, bool const_bh, bool sub)
{
TCGReg orig_rl = rl;
AArch64Insn insn;
@@ -1423,11 +1423,13 @@ static inline void tcg_out_addsub2(TCGContext *s,
TCGType ext, TCGReg rl,
}
if (const_bl) {
- insn = I3401_ADDSI;
- if ((bl < 0) ^ sub) {
- insn = I3401_SUBSI;
+ if (bl < 0) {
bl = -bl;
+ insn = sub ? I3401_ADDSI : I3401_SUBSI;
+ } else {
+ insn = sub ? I3401_SUBSI : I3401_ADDSI;
}
+
if (unlikely(al == TCG_REG_XZR)) {
/* ??? We want to allow al to be zero for the benefit of
negation via subtraction. However, that leaves open the
--
2.25.1
- [PULL 00/27] tcg patch queue, Richard Henderson, 2021/03/06
- [PULL 01/27] tcg/aarch64: Fix constant subtraction in tcg_out_addsub2,
Richard Henderson <=
- [PULL 02/27] tcg/aarch64: Fix I3617_CMLE0, Richard Henderson, 2021/03/06
- [PULL 03/27] tcg/aarch64: Fix generation of "scalar" vector operations, Richard Henderson, 2021/03/06
- [PULL 09/27] tcg/tci: Merge identical cases in generation (deposit opcode), Richard Henderson, 2021/03/06
- [PULL 04/27] tcg/tci: Use exec/cpu_ldst.h interfaces, Richard Henderson, 2021/03/06
- [PULL 12/27] tcg/tci: Remove tci_read_r8, Richard Henderson, 2021/03/06
- [PULL 08/27] tcg/tci: Merge identical cases in generation (exchange opcodes), Richard Henderson, 2021/03/06
- [PULL 11/27] tcg/tci: Merge identical cases in generation (load/store opcodes), Richard Henderson, 2021/03/06
- [PULL 13/27] tcg/tci: Remove tci_read_r8s, Richard Henderson, 2021/03/06
- [PULL 14/27] tcg/tci: Remove tci_read_r16, Richard Henderson, 2021/03/06
- [PULL 15/27] tcg/tci: Remove tci_read_r16s, Richard Henderson, 2021/03/06