1 ; RUN: llc -march=ppc32 -mtriple=powerpc-unknown-linux-gnu -mattr=+altivec < %s | FileCheck %s 2 3 ;; This test ensures that MergeConsecutiveStores does not attempt to 4 ;; merge stores or loads when doing so would result in unaligned 5 ;; memory operations (unless the target supports those, e.g. X86). 6 7 ;; This issue happen in other situations for other targets, but PPC 8 ;; with Altivec extensions was chosen for the test because it does not 9 ;; support unaligned access with AltiVec instructions. If the 4 10 ;; load/stores get merged to an v4i32 vector type severely bad code 11 ;; gets generated: it painstakingly copies the values to a temporary 12 ;; location on the stack, with vector ops, in order to then use 13 ;; integer ops to load from the temporary stack location and store to 14 ;; the final location. Yuck! 15 16 %struct.X = type { i32, i32, i32, i32 } 17 18 @fx = common global %struct.X zeroinitializer, align 4 19 @fy = common global %struct.X zeroinitializer, align 4 20 21 ;; In this test case, lvx and stvx instructions should NOT be 22 ;; generated, as the alignment is not sufficient for it to be 23 ;; worthwhile. 24 25 ;; CHECK-LABEL: f: 26 ;; CHECK: lwzu 27 ;; CHECK-NEXT: lwz 28 ;; CHECK-NEXT: lwz 29 ;; CHECK-NEXT: lwz 30 ;; CHECK-NEXT: stwu 31 ;; CHECK-NEXT: stw 32 ;; CHECK-NEXT: stw 33 ;; CHECK-NEXT: stw 34 ;; CHECK-NEXT: blr 35 define void @f() { 36 entry: 37 %0 = load i32, i32* getelementptr inbounds (%struct.X, %struct.X* @fx, i32 0, i32 0), align 4 38 %1 = load i32, i32* getelementptr inbounds (%struct.X, %struct.X* @fx, i32 0, i32 1), align 4 39 %2 = load i32, i32* getelementptr inbounds (%struct.X, %struct.X* @fx, i32 0, i32 2), align 4 40 %3 = load i32, i32* getelementptr inbounds (%struct.X, %struct.X* @fx, i32 0, i32 3), align 4 41 store i32 %0, i32* getelementptr inbounds (%struct.X, %struct.X* @fy, i32 0, i32 0), align 4 42 store i32 %1, i32* getelementptr inbounds (%struct.X, %struct.X* @fy, i32 0, i32 1), align 4 43 store i32 %2, i32* getelementptr inbounds (%struct.X, %struct.X* @fy, i32 0, i32 2), align 4 44 store i32 %3, i32* getelementptr inbounds (%struct.X, %struct.X* @fy, i32 0, i32 3), align 4 45 ret void 46 } 47 48 @gx = common global %struct.X zeroinitializer, align 16 49 @gy = common global %struct.X zeroinitializer, align 16 50 51 ;; In this test, lvx and stvx instructions SHOULD be generated, as 52 ;; the 16-byte alignment of the new load/store is acceptable. 53 ;; CHECK-LABEL: g: 54 ;; CHECK: lvx 55 ;; CHECK: stvx 56 ;; CHECK: blr 57 define void @g() { 58 entry: 59 %0 = load i32, i32* getelementptr inbounds (%struct.X, %struct.X* @fx, i32 0, i32 0), align 16 60 %1 = load i32, i32* getelementptr inbounds (%struct.X, %struct.X* @fx, i32 0, i32 1), align 4 61 %2 = load i32, i32* getelementptr inbounds (%struct.X, %struct.X* @fx, i32 0, i32 2), align 4 62 %3 = load i32, i32* getelementptr inbounds (%struct.X, %struct.X* @fx, i32 0, i32 3), align 4 63 store i32 %0, i32* getelementptr inbounds (%struct.X, %struct.X* @fy, i32 0, i32 0), align 16 64 store i32 %1, i32* getelementptr inbounds (%struct.X, %struct.X* @fy, i32 0, i32 1), align 4 65 store i32 %2, i32* getelementptr inbounds (%struct.X, %struct.X* @fy, i32 0, i32 2), align 4 66 store i32 %3, i32* getelementptr inbounds (%struct.X, %struct.X* @fy, i32 0, i32 3), align 4 67 ret void 68 } 69
