Add a regression test for tcg indirect global lowering.

This appeared with nios2, with cps != 0, so that we use
indirection into the shadow register set.  An indirect
call verifies alignment of rA.  The use of rA was live
across the brcond leading to a tcg_debug_assert failure.

Cc: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 tests/tcg/nios2/Makefile.softmmu-target |  1 +
 tests/tcg/nios2/test-shadow-1.S         | 37 +++++++++++++++++++++++++
 2 files changed, 38 insertions(+)
 create mode 100644 tests/tcg/nios2/test-shadow-1.S

diff --git a/tests/tcg/nios2/Makefile.softmmu-target b/tests/tcg/nios2/Makefile.softmmu-target
index 70664db81c..b5f6a08848 100644
--- a/tests/tcg/nios2/Makefile.softmmu-target
+++ b/tests/tcg/nios2/Makefile.softmmu-target
@@ -27,3 +27,4 @@ QEMU_OPTS = -M 10m50-ghrd,vic=on -semihosting >$@.out -kernel
 
 memory: CFLAGS+=-DCHECK_UNALIGNED=0
 TESTS += $(MULTIARCH_TESTS)
+TESTS += test-shadow-1
diff --git a/tests/tcg/nios2/test-shadow-1.S b/tests/tcg/nios2/test-shadow-1.S
new file mode 100644
index 0000000000..33076ddf59
--- /dev/null
+++ b/tests/tcg/nios2/test-shadow-1.S
@@ -0,0 +1,37 @@
+/*
+ * Regresion test for TCG indirect global lowering.
+ */
+
+#include "semicall.h"
+
+	.text
+	.set noat
+	.align	2
+	.globl	main
+	.type	main, @function
+
+main:
+	/* Initialize r0 in shadow register set 1. */
+	movhi	at, 1			/* PRS=1, CRS=0, RSIE=0, PIE=0 */
+	wrctl	status, at
+	wrprs	zero, zero
+
+	/* Change current register set to 1. */
+	movi	at, 1 << 10		/* PRS=0, CRS=1, RSIE=0, PIE=0 */
+	wrctl	estatus, at
+	movia	ea, 1f
+	eret
+
+	/* Load address for callr, then end TB. */
+1:	movia	at, 3f
+	br	2f
+
+	/* Test case! TCG abort on indirect lowering across brcond. */
+2:	callr	at
+
+	/* exit(0) */
+3:	movi	r4, HOSTED_EXIT
+	movi	r5, 0
+	semihosting_call
+
+	.size	main, . - main
-- 
2.34.1

On Thu, 21 Apr 2022 at 17:13, Richard Henderson
<richard.henderson@linaro.org> wrote:
>
> Add a regression test for tcg indirect global lowering.
>
> This appeared with nios2, with cps != 0, so that we use
> indirection into the shadow register set.  An indirect
> call verifies alignment of rA.  The use of rA was live
> across the brcond leading to a tcg_debug_assert failure.
>
> Cc: Alex Bennée <alex.bennee@linaro.org>
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>



> +/*
> + * Regresion test for TCG indirect global lowering.

"Regression".

Also, file is missing copyright/license header comment.

Otherwise
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>

thanks
-- PMM