From: Jan Beulich <jbeulich@sourceware.org>
To: binutils-cvs@sourceware.org
Subject: [binutils-gdb] x86: don't suppress errors when optimizing
Date: Fri, 21 Jun 2024 06:36:19 +0000 (GMT) [thread overview]
Message-ID: <20240621063619.8BA553896C0B@sourceware.org> (raw)
https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=c68a6e5cadf333ab3d55443d3aed156415660600
commit c68a6e5cadf333ab3d55443d3aed156415660600
Author: Jan Beulich <jbeulich@suse.com>
Date: Fri Jun 21 08:33:57 2024 +0200
x86: don't suppress errors when optimizing
Blindly ignoring any mnemonic suffix can't be quite right: Bad suffix /
operand combinations still want flagging. Simply avoid optimizing in
such situations.
Diff:
---
gas/config/tc-i386.c | 17 ++++++++++++++++-
gas/testsuite/gas/i386/i386.exp | 1 +
gas/testsuite/gas/i386/optimize-8.l | 4 ++++
gas/testsuite/gas/i386/optimize-8.s | 6 ++++++
4 files changed, 27 insertions(+), 1 deletion(-)
diff --git a/gas/config/tc-i386.c b/gas/config/tc-i386.c
index b8fc3c43819..b8911c04436 100644
--- a/gas/config/tc-i386.c
+++ b/gas/config/tc-i386.c
@@ -4573,6 +4573,20 @@ check_hle (void)
}
}
+/* Helper for optimization (running ahead of process_suffix()), to make sure we
+ convert only well-formed insns. @OP is the sized operand to cross check
+ against (typically a register). Checking against a single operand typically
+ suffices, as match_template() has already honored CheckOperandSize. */
+
+static bool is_plausible_suffix (unsigned int op)
+{
+ return !i.suffix
+ || (i.suffix == BYTE_MNEM_SUFFIX && i.types[op].bitfield.byte)
+ || (i.suffix == WORD_MNEM_SUFFIX && i.types[op].bitfield.word)
+ || (i.suffix == LONG_MNEM_SUFFIX && i.types[op].bitfield.dword)
+ || (i.suffix == QWORD_MNEM_SUFFIX && i.types[op].bitfield.qword);
+}
+
/* Encode aligned vector move as unaligned vector move. */
static void
@@ -4758,6 +4772,7 @@ optimize_encoding (void)
&& i.reg_operands == 1
&& i.imm_operands == 1
&& !i.types[1].bitfield.byte
+ && is_plausible_suffix (1)
&& i.op[0].imms->X_op == O_constant
&& fits_in_imm7 (i.op[0].imms->X_add_number))
{
@@ -4768,7 +4783,7 @@ optimize_encoding (void)
if (flag_code == CODE_64BIT || base_regnum < 4)
{
i.types[1].bitfield.byte = 1;
- /* Ignore the suffix. */
+ /* Squash the suffix. */
i.suffix = 0;
/* Convert to byte registers. 8-bit registers are special,
RegRex64 and non-RegRex64 each have 8 registers. */
diff --git a/gas/testsuite/gas/i386/i386.exp b/gas/testsuite/gas/i386/i386.exp
index 2584c69bddc..e40b45fe990 100644
--- a/gas/testsuite/gas/i386/i386.exp
+++ b/gas/testsuite/gas/i386/i386.exp
@@ -615,6 +615,7 @@ if [gas_32_check] then {
run_list_test "optimize-6a" "-I${srcdir}/$subdir -march=+noavx -al"
run_dump_test "optimize-6b"
run_list_test "optimize-7" "-I${srcdir}/$subdir -march=+noavx2 -al"
+ run_list_test "optimize-8" "-Os"
run_dump_test "noopt"
run_dump_test "lea-optimize"
run_dump_test "lea16-optimize"
diff --git a/gas/testsuite/gas/i386/optimize-8.l b/gas/testsuite/gas/i386/optimize-8.l
new file mode 100644
index 00000000000..af97d73a086
--- /dev/null
+++ b/gas/testsuite/gas/i386/optimize-8.l
@@ -0,0 +1,4 @@
+.*: Assembler messages:
+.*:5: Error: .* `%ecx' .* suffix
+.*:6: Error: .* `%cx' .* suffix
+#pass
diff --git a/gas/testsuite/gas/i386/optimize-8.s b/gas/testsuite/gas/i386/optimize-8.s
new file mode 100644
index 00000000000..9b68189f91d
--- /dev/null
+++ b/gas/testsuite/gas/i386/optimize-8.s
@@ -0,0 +1,6 @@
+# Check bogus instructions are still rejected when optimizing
+
+ .text
+_start:
+ testw $4, %ecx
+ testl $4, %cx
reply other threads:[~2024-06-21 6:36 UTC|newest]
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