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-rw-r--r--tcg/riscv/tcg-target.c.inc19
1 files changed, 16 insertions, 3 deletions
diff --git a/tcg/riscv/tcg-target.c.inc b/tcg/riscv/tcg-target.c.inc
index 81a83e4..1911978 100644
--- a/tcg/riscv/tcg-target.c.inc
+++ b/tcg/riscv/tcg-target.c.inc
@@ -154,13 +154,26 @@ static bool tcg_target_const_match(int64_t val, TCGType type, int ct)
if ((ct & TCG_CT_CONST_ZERO) && val == 0) {
return 1;
}
- if ((ct & TCG_CT_CONST_S12) && val == sextreg(val, 0, 12)) {
+ /*
+ * Sign extended from 12 bits: [-0x800, 0x7ff].
+ * Used for most arithmetic, as this is the isa field.
+ */
+ if ((ct & TCG_CT_CONST_S12) && val >= -0x800 && val <= 0x7ff) {
return 1;
}
- if ((ct & TCG_CT_CONST_N12) && -val == sextreg(-val, 0, 12)) {
+ /*
+ * Sign extended from 12 bits, negated: [-0x7ff, 0x800].
+ * Used for subtraction, where a constant must be handled by ADDI.
+ */
+ if ((ct & TCG_CT_CONST_N12) && val >= -0x7ff && val <= 0x800) {
return 1;
}
- if ((ct & TCG_CT_CONST_M12) && val >= -0xfff && val <= 0xfff) {
+ /*
+ * Sign extended from 12 bits, +/- matching: [-0x7ff, 0x7ff].
+ * Used by addsub2, which may need the negative operation,
+ * and requires the modified constant to be representable.
+ */
+ if ((ct & TCG_CT_CONST_M12) && val >= -0x7ff && val <= 0x7ff) {
return 1;
}
return 0;