From c42b725ce9da8058ff6a4cd28bf6b92a4527a285 Mon Sep 17 00:00:00 2001
From: Afonso Bordado <afonsobordado@az8.co>
Date: Sun, 4 Jul 2021 10:55:44 +0100
Subject: [PATCH] cranelift: Fix br_icmp in interpreter

---
 .../filetests/filetests/runtests/br_icmp.clif | 767 ++++++++++++++++++
 cranelift/interpreter/src/step.rs             |  13 +-
 2 files changed, 778 insertions(+), 2 deletions(-)
 create mode 100644 cranelift/filetests/filetests/runtests/br_icmp.clif

diff --git a/cranelift/filetests/filetests/runtests/br_icmp.clif b/cranelift/filetests/filetests/runtests/br_icmp.clif
new file mode 100644
index 0000000000..cfb448a33b
--- /dev/null
+++ b/cranelift/filetests/filetests/runtests/br_icmp.clif
@@ -0,0 +1,767 @@
+test interpret
+test run
+target aarch64
+target s390x
+target x86_64 machinst
+
+
+function %bricmp_eq_i64(i64, i64) -> b1 {
+block0(v0: i64, v1: i64):
+    br_icmp.i64 eq v0, v1, block2
+    jump block1
+
+block1:
+    v2 = bconst.b1 false
+    return v2
+
+block2:
+    v3 = bconst.b1 true
+    return v3
+}
+; run: %bricmp_eq_i64(0, 0) == true
+; run: %bricmp_eq_i64(0, 1) == false
+; run: %bricmp_eq_i64(1, 0) == false
+; run: %bricmp_eq_i64(0xC0FFEEEE_DECAFFFF, 0xDECAFFFF_C0FFEEEE) == false
+
+function %bricmp_eq_i32(i32, i32) -> b1 {
+block0(v0: i32, v1: i32):
+    br_icmp.i32 eq v0, v1, block2
+    jump block1
+
+block1:
+    v2 = bconst.b1 false
+    return v2
+
+block2:
+    v3 = bconst.b1 true
+    return v3
+}
+; run: %bricmp_eq_i32(0, 0) == true
+; run: %bricmp_eq_i32(0, 1) == false
+; run: %bricmp_eq_i32(1, 0) == false
+; run: %bricmp_eq_i32(0xC0FFEEEE, 0xDECAFFFF) == false
+
+function %bricmp_eq_i16(i16, i16) -> b1 {
+block0(v0: i16, v1: i16):
+    br_icmp.i16 eq v0, v1, block2
+    jump block1
+
+block1:
+    v2 = bconst.b1 false
+    return v2
+
+block2:
+    v3 = bconst.b1 true
+    return v3
+}
+; run: %bricmp_eq_i16(0, 0) == true
+; run: %bricmp_eq_i16(0, 1) == false
+; run: %bricmp_eq_i16(1, 0) == false
+; run: %bricmp_eq_i16(0xC0FF, 0xDECA) == false
+
+function %bricmp_eq_i8(i8, i8) -> b1 {
+block0(v0: i8, v1: i8):
+    br_icmp.i8 eq v0, v1, block2
+    jump block1
+
+block1:
+    v2 = bconst.b1 false
+    return v2
+
+block2:
+    v3 = bconst.b1 true
+    return v3
+}
+; run: %bricmp_eq_i8(0, 0) == true
+; run: %bricmp_eq_i8(0, 1) == false
+; run: %bricmp_eq_i8(1, 0) == false
+; run: %bricmp_eq_i8(0xC0, 0xDE) == false
+
+
+function %bricmp_ne_i64(i64, i64) -> b1 {
+block0(v0: i64, v1: i64):
+    br_icmp.i64 ne v0, v1, block2
+    jump block1
+
+block1:
+    v2 = bconst.b1 false
+    return v2
+
+block2:
+    v3 = bconst.b1 true
+    return v3
+}
+; run: %bricmp_ne_i64(0, 0) == false
+; run: %bricmp_ne_i64(0, 1) == true
+; run: %bricmp_ne_i64(1, 0) == true
+; run: %bricmp_ne_i64(0xC0FFEEEE_DECAFFFF, 0xDECAFFFF_C0FFEEEE) == true
+
+function %bricmp_ne_i32(i32, i32) -> b1 {
+block0(v0: i32, v1: i32):
+    br_icmp.i32 ne v0, v1, block2
+    jump block1
+
+block1:
+    v2 = bconst.b1 false
+    return v2
+
+block2:
+    v3 = bconst.b1 true
+    return v3
+}
+; run: %bricmp_ne_i32(0, 0) == false
+; run: %bricmp_ne_i32(0, 1) == true
+; run: %bricmp_ne_i32(1, 0) == true
+; run: %bricmp_ne_i32(0xC0FFEEEE, 0xDECAFFFF) == true
+
+function %bricmp_ne_i16(i16, i16) -> b1 {
+block0(v0: i16, v1: i16):
+    br_icmp.i16 ne v0, v1, block2
+    jump block1
+
+block1:
+    v2 = bconst.b1 false
+    return v2
+
+block2:
+    v3 = bconst.b1 true
+    return v3
+}
+; run: %bricmp_ne_i16(0, 0) == false
+; run: %bricmp_ne_i16(0, 1) == true
+; run: %bricmp_ne_i16(1, 0) == true
+; run: %bricmp_ne_i16(0xC0FF, 0xDECA) == true
+
+function %bricmp_ne_i8(i8, i8) -> b1 {
+block0(v0: i8, v1: i8):
+    br_icmp.i8 ne v0, v1, block2
+    jump block1
+
+block1:
+    v2 = bconst.b1 false
+    return v2
+
+block2:
+    v3 = bconst.b1 true
+    return v3
+}
+; run: %bricmp_ne_i8(0, 0) == false
+; run: %bricmp_ne_i8(0, 1) == true
+; run: %bricmp_ne_i8(1, 0) == true
+; run: %bricmp_ne_i8(0xC0, 0xDE) == true
+
+
+function %bricmp_slt_i64(i64, i64) -> b1 {
+block0(v0: i64, v1: i64):
+    br_icmp.i64 slt v0, v1, block2
+    jump block1
+
+block1:
+    v2 = bconst.b1 false
+    return v2
+
+block2:
+    v3 = bconst.b1 true
+    return v3
+}
+; run: %bricmp_slt_i64(0, 0) == false
+; run: %bricmp_slt_i64(0, 1) == true
+; run: %bricmp_slt_i64(1, 0) == false
+; run: %bricmp_slt_i64(0, -1) == false
+; run: %bricmp_slt_i64(-1, 0) == true
+
+function %bricmp_slt_i32(i32, i32) -> b1 {
+block0(v0: i32, v1: i32):
+    br_icmp.i32 slt v0, v1, block2
+    jump block1
+
+block1:
+    v2 = bconst.b1 false
+    return v2
+
+block2:
+    v3 = bconst.b1 true
+    return v3
+}
+; run: %bricmp_slt_i32(0, 0) == false
+; run: %bricmp_slt_i32(0, 1) == true
+; run: %bricmp_slt_i32(1, 0) == false
+; run: %bricmp_slt_i32(0, -1) == false
+; run: %bricmp_slt_i32(-1, 0) == true
+
+function %bricmp_slt_i16(i16, i16) -> b1 {
+block0(v0: i16, v1: i16):
+    br_icmp.i16 slt v0, v1, block2
+    jump block1
+
+block1:
+    v2 = bconst.b1 false
+    return v2
+
+block2:
+    v3 = bconst.b1 true
+    return v3
+}
+; run: %bricmp_slt_i16(0, 0) == false
+; run: %bricmp_slt_i16(0, 1) == true
+; run: %bricmp_slt_i16(1, 0) == false
+; run: %bricmp_slt_i16(0, -1) == false
+; run: %bricmp_slt_i16(-1, 0) == true
+
+function %bricmp_slt_i8(i8, i8) -> b1 {
+block0(v0: i8, v1: i8):
+    br_icmp.i8 slt v0, v1, block2
+    jump block1
+
+block1:
+    v2 = bconst.b1 false
+    return v2
+
+block2:
+    v3 = bconst.b1 true
+    return v3
+}
+; run: %bricmp_slt_i8(0, 0) == false
+; run: %bricmp_slt_i8(0, 1) == true
+; run: %bricmp_slt_i8(1, 0) == false
+; run: %bricmp_slt_i8(0, -1) == false
+; run: %bricmp_slt_i8(-1, 0) == true
+
+
+function %bricmp_ult_i64(i64, i64) -> b1 {
+block0(v0: i64, v1: i64):
+    br_icmp.i64 ult v0, v1, block2
+    jump block1
+
+block1:
+    v2 = bconst.b1 false
+    return v2
+
+block2:
+    v3 = bconst.b1 true
+    return v3
+}
+; run: %bricmp_ult_i64(0, 0) == false
+; run: %bricmp_ult_i64(0, 1) == true
+; run: %bricmp_ult_i64(1, 0) == false
+; run: %bricmp_ult_i64(0, -1) == true
+; run: %bricmp_ult_i64(-1, 0) == false
+
+function %bricmp_ult_i32(i32, i32) -> b1 {
+block0(v0: i32, v1: i32):
+    br_icmp.i32 ult v0, v1, block2
+    jump block1
+
+block1:
+    v2 = bconst.b1 false
+    return v2
+
+block2:
+    v3 = bconst.b1 true
+    return v3
+}
+; run: %bricmp_ult_i32(0, 0) == false
+; run: %bricmp_ult_i32(0, 1) == true
+; run: %bricmp_ult_i32(1, 0) == false
+; run: %bricmp_ult_i32(0, -1) == true
+; run: %bricmp_ult_i32(-1, 0) == false
+
+function %bricmp_ult_i16(i16, i16) -> b1 {
+block0(v0: i16, v1: i16):
+    br_icmp.i16 ult v0, v1, block2
+    jump block1
+
+block1:
+    v2 = bconst.b1 false
+    return v2
+
+block2:
+    v3 = bconst.b1 true
+    return v3
+}
+; run: %bricmp_ult_i16(0, 0) == false
+; run: %bricmp_ult_i16(0, 1) == true
+; run: %bricmp_ult_i16(1, 0) == false
+; run: %bricmp_ult_i16(0, -1) == true
+; run: %bricmp_ult_i16(-1, 0) == false
+
+function %bricmp_ult_i8(i8, i8) -> b1 {
+block0(v0: i8, v1: i8):
+    br_icmp.i8 ult v0, v1, block2
+    jump block1
+
+block1:
+    v2 = bconst.b1 false
+    return v2
+
+block2:
+    v3 = bconst.b1 true
+    return v3
+}
+; run: %bricmp_ult_i8(0, 0) == false
+; run: %bricmp_ult_i8(0, 1) == true
+; run: %bricmp_ult_i8(1, 0) == false
+; run: %bricmp_ult_i8(0, -1) == true
+; run: %bricmp_ult_i8(-1, 0) == false
+
+
+function %bricmp_sle_i64(i64, i64) -> b1 {
+block0(v0: i64, v1: i64):
+    br_icmp.i64 sle v0, v1, block2
+    jump block1
+
+block1:
+    v2 = bconst.b1 false
+    return v2
+
+block2:
+    v3 = bconst.b1 true
+    return v3
+}
+; run: %bricmp_sle_i64(0, 0) == true
+; run: %bricmp_sle_i64(0, 1) == true
+; run: %bricmp_sle_i64(1, 0) == false
+; run: %bricmp_sle_i64(0, -1) == false
+; run: %bricmp_sle_i64(-1, 0) == true
+
+function %bricmp_sle_i32(i32, i32) -> b1 {
+block0(v0: i32, v1: i32):
+    br_icmp.i32 sle v0, v1, block2
+    jump block1
+
+block1:
+    v2 = bconst.b1 false
+    return v2
+
+block2:
+    v3 = bconst.b1 true
+    return v3
+}
+; run: %bricmp_sle_i32(0, 0) == true
+; run: %bricmp_sle_i32(0, 1) == true
+; run: %bricmp_sle_i32(1, 0) == false
+; run: %bricmp_sle_i32(0, -1) == false
+; run: %bricmp_sle_i32(-1, 0) == true
+
+function %bricmp_sle_i16(i16, i16) -> b1 {
+block0(v0: i16, v1: i16):
+    br_icmp.i16 sle v0, v1, block2
+    jump block1
+
+block1:
+    v2 = bconst.b1 false
+    return v2
+
+block2:
+    v3 = bconst.b1 true
+    return v3
+}
+; run: %bricmp_sle_i16(0, 0) == true
+; run: %bricmp_sle_i16(0, 1) == true
+; run: %bricmp_sle_i16(1, 0) == false
+; run: %bricmp_sle_i16(0, -1) == false
+; run: %bricmp_sle_i16(-1, 0) == true
+
+function %bricmp_sle_i8(i8, i8) -> b1 {
+block0(v0: i8, v1: i8):
+    br_icmp.i8 sle v0, v1, block2
+    jump block1
+
+block1:
+    v2 = bconst.b1 false
+    return v2
+
+block2:
+    v3 = bconst.b1 true
+    return v3
+}
+; run: %bricmp_sle_i8(0, 0) == true
+; run: %bricmp_sle_i8(0, 1) == true
+; run: %bricmp_sle_i8(1, 0) == false
+; run: %bricmp_sle_i8(0, -1) == false
+; run: %bricmp_sle_i8(-1, 0) == true
+
+
+function %bricmp_ule_i64(i64, i64) -> b1 {
+block0(v0: i64, v1: i64):
+    br_icmp.i64 ule v0, v1, block2
+    jump block1
+
+block1:
+    v2 = bconst.b1 false
+    return v2
+
+block2:
+    v3 = bconst.b1 true
+    return v3
+}
+; run: %bricmp_ule_i64(0, 0) == true
+; run: %bricmp_ule_i64(0, 1) == true
+; run: %bricmp_ule_i64(1, 0) == false
+; run: %bricmp_ule_i64(0, -1) == true
+; run: %bricmp_ule_i64(-1, 0) == false
+
+function %bricmp_ule_i32(i32, i32) -> b1 {
+block0(v0: i32, v1: i32):
+    br_icmp.i32 ule v0, v1, block2
+    jump block1
+
+block1:
+    v2 = bconst.b1 false
+    return v2
+
+block2:
+    v3 = bconst.b1 true
+    return v3
+}
+; run: %bricmp_ule_i32(0, 0) == true
+; run: %bricmp_ule_i32(0, 1) == true
+; run: %bricmp_ule_i32(1, 0) == false
+; run: %bricmp_ule_i32(0, -1) == true
+; run: %bricmp_ule_i32(-1, 0) == false
+
+function %bricmp_ule_i16(i16, i16) -> b1 {
+block0(v0: i16, v1: i16):
+    br_icmp.i16 ule v0, v1, block2
+    jump block1
+
+block1:
+    v2 = bconst.b1 false
+    return v2
+
+block2:
+    v3 = bconst.b1 true
+    return v3
+}
+; run: %bricmp_ule_i16(0, 0) == true
+; run: %bricmp_ule_i16(0, 1) == true
+; run: %bricmp_ule_i16(1, 0) == false
+; run: %bricmp_ule_i16(0, -1) == true
+; run: %bricmp_ule_i16(-1, 0) == false
+
+function %bricmp_ule_i8(i8, i8) -> b1 {
+block0(v0: i8, v1: i8):
+    br_icmp.i8 ule v0, v1, block2
+    jump block1
+
+block1:
+    v2 = bconst.b1 false
+    return v2
+
+block2:
+    v3 = bconst.b1 true
+    return v3
+}
+; run: %bricmp_ule_i8(0, 0) == true
+; run: %bricmp_ule_i8(0, 1) == true
+; run: %bricmp_ule_i8(1, 0) == false
+; run: %bricmp_ule_i8(0, -1) == true
+; run: %bricmp_ule_i8(-1, 0) == false
+
+
+function %bricmp_sgt_i64(i64, i64) -> b1 {
+block0(v0: i64, v1: i64):
+    br_icmp.i64 sgt v0, v1, block2
+    jump block1
+
+block1:
+    v2 = bconst.b1 false
+    return v2
+
+block2:
+    v3 = bconst.b1 true
+    return v3
+}
+; run: %bricmp_sgt_i64(0, 0) == false
+; run: %bricmp_sgt_i64(0, 1) == false
+; run: %bricmp_sgt_i64(1, 0) == true
+; run: %bricmp_sgt_i64(0, -1) == true
+; run: %bricmp_sgt_i64(-1, 0) == false
+
+function %bricmp_sgt_i32(i32, i32) -> b1 {
+block0(v0: i32, v1: i32):
+    br_icmp.i32 sgt v0, v1, block2
+    jump block1
+
+block1:
+    v2 = bconst.b1 false
+    return v2
+
+block2:
+    v3 = bconst.b1 true
+    return v3
+}
+; run: %bricmp_sgt_i32(0, 0) == false
+; run: %bricmp_sgt_i32(0, 1) == false
+; run: %bricmp_sgt_i32(1, 0) == true
+; run: %bricmp_sgt_i32(0, -1) == true
+; run: %bricmp_sgt_i32(-1, 0) == false
+
+function %bricmp_sgt_i16(i16, i16) -> b1 {
+block0(v0: i16, v1: i16):
+    br_icmp.i16 sgt v0, v1, block2
+    jump block1
+
+block1:
+    v2 = bconst.b1 false
+    return v2
+
+block2:
+    v3 = bconst.b1 true
+    return v3
+}
+; run: %bricmp_sgt_i16(0, 0) == false
+; run: %bricmp_sgt_i16(0, 1) == false
+; run: %bricmp_sgt_i16(1, 0) == true
+; run: %bricmp_sgt_i16(0, -1) == true
+; run: %bricmp_sgt_i16(-1, 0) == false
+
+function %bricmp_sgt_i8(i8, i8) -> b1 {
+block0(v0: i8, v1: i8):
+    br_icmp.i8 sgt v0, v1, block2
+    jump block1
+
+block1:
+    v2 = bconst.b1 false
+    return v2
+
+block2:
+    v3 = bconst.b1 true
+    return v3
+}
+; run: %bricmp_sgt_i8(0, 0) == false
+; run: %bricmp_sgt_i8(0, 1) == false
+; run: %bricmp_sgt_i8(1, 0) == true
+; run: %bricmp_sgt_i8(0, -1) == true
+; run: %bricmp_sgt_i8(-1, 0) == false
+
+
+function %bricmp_ugt_i64(i64, i64) -> b1 {
+block0(v0: i64, v1: i64):
+    br_icmp.i64 ugt v0, v1, block2
+    jump block1
+
+block1:
+    v2 = bconst.b1 false
+    return v2
+
+block2:
+    v3 = bconst.b1 true
+    return v3
+}
+; run: %bricmp_ugt_i64(0, 0) == false
+; run: %bricmp_ugt_i64(0, 1) == false
+; run: %bricmp_ugt_i64(1, 0) == true
+; run: %bricmp_ugt_i64(0, -1) == false
+; run: %bricmp_ugt_i64(-1, 0) == true
+
+function %bricmp_ugt_i32(i32, i32) -> b1 {
+block0(v0: i32, v1: i32):
+    br_icmp.i32 ugt v0, v1, block2
+    jump block1
+
+block1:
+    v2 = bconst.b1 false
+    return v2
+
+block2:
+    v3 = bconst.b1 true
+    return v3
+}
+; run: %bricmp_ugt_i32(0, 0) == false
+; run: %bricmp_ugt_i32(0, 1) == false
+; run: %bricmp_ugt_i32(1, 0) == true
+; run: %bricmp_ugt_i32(0, -1) == false
+; run: %bricmp_ugt_i32(-1, 0) == true
+
+function %bricmp_ugt_i16(i16, i16) -> b1 {
+block0(v0: i16, v1: i16):
+    br_icmp.i16 ugt v0, v1, block2
+    jump block1
+
+block1:
+    v2 = bconst.b1 false
+    return v2
+
+block2:
+    v3 = bconst.b1 true
+    return v3
+}
+; run: %bricmp_ugt_i16(0, 0) == false
+; run: %bricmp_ugt_i16(0, 1) == false
+; run: %bricmp_ugt_i16(1, 0) == true
+; run: %bricmp_ugt_i16(0, -1) == false
+; run: %bricmp_ugt_i16(-1, 0) == true
+
+function %bricmp_ugt_i8(i8, i8) -> b1 {
+block0(v0: i8, v1: i8):
+    br_icmp.i8 ugt v0, v1, block2
+    jump block1
+
+block1:
+    v2 = bconst.b1 false
+    return v2
+
+block2:
+    v3 = bconst.b1 true
+    return v3
+}
+; run: %bricmp_ugt_i8(0, 0) == false
+; run: %bricmp_ugt_i8(0, 1) == false
+; run: %bricmp_ugt_i8(1, 0) == true
+; run: %bricmp_ugt_i8(0, -1) == false
+; run: %bricmp_ugt_i8(-1, 0) == true
+
+
+function %bricmp_sge_i64(i64, i64) -> b1 {
+block0(v0: i64, v1: i64):
+    br_icmp.i64 sge v0, v1, block2
+    jump block1
+
+block1:
+    v2 = bconst.b1 false
+    return v2
+
+block2:
+    v3 = bconst.b1 true
+    return v3
+}
+; run: %bricmp_sge_i64(0, 0) == true
+; run: %bricmp_sge_i64(0, 1) == false
+; run: %bricmp_sge_i64(1, 0) == true
+; run: %bricmp_sge_i64(0, -1) == true
+; run: %bricmp_sge_i64(-1, 0) == false
+
+function %bricmp_sge_i32(i32, i32) -> b1 {
+block0(v0: i32, v1: i32):
+    br_icmp.i32 sge v0, v1, block2
+    jump block1
+
+block1:
+    v2 = bconst.b1 false
+    return v2
+
+block2:
+    v3 = bconst.b1 true
+    return v3
+}
+; run: %bricmp_sge_i32(0, 0) == true
+; run: %bricmp_sge_i32(0, 1) == false
+; run: %bricmp_sge_i32(1, 0) == true
+; run: %bricmp_sge_i32(0, -1) == true
+; run: %bricmp_sge_i32(-1, 0) == false
+
+function %bricmp_sge_i16(i16, i16) -> b1 {
+block0(v0: i16, v1: i16):
+    br_icmp.i16 sge v0, v1, block2
+    jump block1
+
+block1:
+    v2 = bconst.b1 false
+    return v2
+
+block2:
+    v3 = bconst.b1 true
+    return v3
+}
+; run: %bricmp_sge_i16(0, 0) == true
+; run: %bricmp_sge_i16(0, 1) == false
+; run: %bricmp_sge_i16(1, 0) == true
+; run: %bricmp_sge_i16(0, -1) == true
+; run: %bricmp_sge_i16(-1, 0) == false
+
+function %bricmp_sge_i8(i8, i8) -> b1 {
+block0(v0: i8, v1: i8):
+    br_icmp.i8 sge v0, v1, block2
+    jump block1
+
+block1:
+    v2 = bconst.b1 false
+    return v2
+
+block2:
+    v3 = bconst.b1 true
+    return v3
+}
+; run: %bricmp_sge_i8(0, 0) == true
+; run: %bricmp_sge_i8(0, 1) == false
+; run: %bricmp_sge_i8(1, 0) == true
+; run: %bricmp_sge_i8(0, -1) == true
+; run: %bricmp_sge_i8(-1, 0) == false
+
+
+function %bricmp_uge_i64(i64, i64) -> b1 {
+block0(v0: i64, v1: i64):
+    br_icmp.i64 uge v0, v1, block2
+    jump block1
+
+block1:
+    v2 = bconst.b1 false
+    return v2
+
+block2:
+    v3 = bconst.b1 true
+    return v3
+}
+; run: %bricmp_uge_i64(0, 0) == true
+; run: %bricmp_uge_i64(0, 1) == false
+; run: %bricmp_uge_i64(1, 0) == true
+; run: %bricmp_uge_i64(0, -1) == false
+; run: %bricmp_uge_i64(-1, 0) == true
+
+function %bricmp_uge_i32(i32, i32) -> b1 {
+block0(v0: i32, v1: i32):
+    br_icmp.i32 uge v0, v1, block2
+    jump block1
+
+block1:
+    v2 = bconst.b1 false
+    return v2
+
+block2:
+    v3 = bconst.b1 true
+    return v3
+}
+; run: %bricmp_uge_i32(0, 0) == true
+; run: %bricmp_uge_i32(0, 1) == false
+; run: %bricmp_uge_i32(1, 0) == true
+; run: %bricmp_uge_i32(0, -1) == false
+; run: %bricmp_uge_i32(-1, 0) == true
+
+function %bricmp_uge_i16(i16, i16) -> b1 {
+block0(v0: i16, v1: i16):
+    br_icmp.i16 uge v0, v1, block2
+    jump block1
+
+block1:
+    v2 = bconst.b1 false
+    return v2
+
+block2:
+    v3 = bconst.b1 true
+    return v3
+}
+; run: %bricmp_uge_i16(0, 0) == true
+; run: %bricmp_uge_i16(0, 1) == false
+; run: %bricmp_uge_i16(1, 0) == true
+; run: %bricmp_uge_i16(0, -1) == false
+; run: %bricmp_uge_i16(-1, 0) == true
+
+function %bricmp_uge_i8(i8, i8) -> b1 {
+block0(v0: i8, v1: i8):
+    br_icmp.i8 uge v0, v1, block2
+    jump block1
+
+block1:
+    v2 = bconst.b1 false
+    return v2
+
+block2:
+    v3 = bconst.b1 true
+    return v3
+}
+; run: %bricmp_uge_i8(0, 0) == true
+; run: %bricmp_uge_i8(0, 1) == false
+; run: %bricmp_uge_i8(1, 0) == true
+; run: %bricmp_uge_i8(0, -1) == false
+; run: %bricmp_uge_i8(-1, 0) == true
diff --git a/cranelift/interpreter/src/step.rs b/cranelift/interpreter/src/step.rs
index d69ef602c6..28699b8273 100644
--- a/cranelift/interpreter/src/step.rs
+++ b/cranelift/interpreter/src/step.rs
@@ -102,8 +102,17 @@ where
 
     // Based on `condition`, indicate where to continue the control flow.
     let branch_when = |condition: bool| -> Result<ControlFlow<V>, StepError> {
+        let branch_args = match inst {
+            InstructionData::Jump { .. } => args_range(0..),
+            InstructionData::BranchInt { .. }
+            | InstructionData::BranchFloat { .. }
+            | InstructionData::Branch { .. } => args_range(1..),
+            InstructionData::BranchIcmp { .. } => args_range(2..),
+            _ => panic!("Unrecognized branch inst: {:?}", inst),
+        }?;
+
         Ok(if condition {
-            ControlFlow::ContinueAt(branch(), args_range(1..)?)
+            ControlFlow::ContinueAt(branch(), branch_args)
         } else {
             ControlFlow::Continue
         })
@@ -143,7 +152,7 @@ where
             ty if ty.is_int() => arg(0)?.into_int()? != 0,
             _ => return Err(StepError::ValueError(ValueError::InvalidValue(types::B1))),
         })?,
-        Opcode::BrIcmp => branch_when(icmp(inst.cond_code().unwrap(), &arg(1)?, &arg(2)?)?)?,
+        Opcode::BrIcmp => branch_when(icmp(inst.cond_code().unwrap(), &arg(0)?, &arg(1)?)?)?,
         Opcode::Brif => branch_when(state.has_iflag(inst.cond_code().unwrap()))?,
         Opcode::Brff => branch_when(state.has_fflag(inst.fp_cond_code().unwrap()))?,
         Opcode::BrTable => unimplemented!("BrTable"),