This is the mail archive of the
binutils@sourceware.org
mailing list for the binutils project.
ubsan: epiphany: left shift of negative value
- From: Alan Modra <amodra at gmail dot com>
- To: binutils at sourceware dot org
- Date: Wed, 11 Dec 2019 11:16:39 +1030
- Subject: ubsan: epiphany: left shift of negative value
Two places in epiphany_cgen_extract_operand, "value" is a long.
value = ((((value) << (1))) + (pc));
cpu/
* epiphany.cpu (f-simm8, f-simm24): Use multiply rather than
shift left to avoid UB on left shift of negative values.
opcodes/
* epiphany-ibld.c: Regenerate.
diff --git a/cpu/epiphany.cpu b/cpu/epiphany.cpu
index 33c81d004f..9f873b38f4 100644
--- a/cpu/epiphany.cpu
+++ b/cpu/epiphany.cpu
@@ -149,11 +149,11 @@
(df f-simm8 "branch displacement" (PCREL-ADDR RELOC) 15 8 INT
((value pc) (sra SI (sub SI value pc) 1))
- ((value pc) (add SI (sll SI value 1) pc)))
+ ((value pc) (add SI (mul SI value 2) pc)))
(df f-simm24 "branch displacement" (PCREL-ADDR RELOC) 31 24 INT
((value pc) (sra SI (sub SI value pc) 1))
- ((value pc) (add SI (sll SI value 1) pc)))
+ ((value pc) (add SI (mul SI value 2) pc)))
(df f-sdisp3 "signed immediate 3 bit" () 9 3 INT #f #f)
diff --git a/opcodes/epiphany-ibld.c b/opcodes/epiphany-ibld.c
index 83cfaf3fb8..6e6fd7be97 100644
--- a/opcodes/epiphany-ibld.c
+++ b/opcodes/epiphany-ibld.c
@@ -1100,7 +1100,7 @@ epiphany_cgen_extract_operand (CGEN_CPU_DESC cd,
{
long value;
length = extract_normal (cd, ex_info, insn_value, 0|(1<<CGEN_IFLD_SIGNED)|(1<<CGEN_IFLD_RELOC)|(1<<CGEN_IFLD_PCREL_ADDR), 0, 31, 24, 32, total_length, pc, & value);
- value = ((((value) << (1))) + (pc));
+ value = ((((value) * (2))) + (pc));
fields->f_simm24 = value;
}
break;
@@ -1111,7 +1111,7 @@ epiphany_cgen_extract_operand (CGEN_CPU_DESC cd,
{
long value;
length = extract_normal (cd, ex_info, insn_value, 0|(1<<CGEN_IFLD_SIGNED)|(1<<CGEN_IFLD_RELOC)|(1<<CGEN_IFLD_PCREL_ADDR), 0, 15, 8, 32, total_length, pc, & value);
- value = ((((value) << (1))) + (pc));
+ value = ((((value) * (2))) + (pc));
fields->f_simm8 = value;
}
break;
--
Alan Modra
Australia Development Lab, IBM